+-----------+----------------------------------------------------------+
| ![](m     | **Preview Information in Cab Displays for High-Speed     |
| edia/imag | Locomotives**                                            |
| e1.wmf){w |                                                          |
| idth="2.9 |                                                          |
| 895833333 |                                                          |
| 333335in" |                                                          |
| height="  |                                                          |
| 1.4486111 |                                                          |
| 11111111i |                                                          |
| n"}![](me |                                                          |
| dia/image |                                                          |
| 2.wmf){wi |                                                          |
| dth="0.46 |                                                          |
| 111111111 |                                                          |
| 111114in" |                                                          |
| hei       |                                                          |
| ght="0.50 |                                                          |
| 347222222 |                                                          |
| 22222in"} |                                                          |
|           |                                                          |
| U.S.      |                                                          |
| D         |                                                          |
| epartment |                                                          |
|           |                                                          |
| of        |                                                          |
| Trans     |                                                          |
| portation |                                                          |
|           |                                                          |
| **Federal |                                                          |
| R         |                                                          |
| ailroad** |                                                          |
|           |                                                          |
| **Adminis |                                                          |
| tration** |                                                          |
+-----------+----------------------------------------------------------+

+----------------------+-----------------------------------------------+
| Office of Research   | U.S. Department of Transportation             |
|                      |                                               |
| and Development      | Research and Special Programs Administration  |
|                      |                                               |
| Washington, DC 20590 | John A. Volpe National Transportation Systems |
|                      | Center                                        |
|                      |                                               |
|                      | Cambridge, MA 02142                           |
+----------------------+-----------------------------------------------+

![](media/image3.png){width="5.5in" height="3.251388888888889in"}

+------------------------+--------------------+------------------------+
| DOT/FRA/ORD-04/12      | > Final Report     | This document is       |
|                        | >                  | available to the       |
|                        | > July 2005        |                        |
|                        |                    | public through the     |
|                        |                    | National Technical     |
|                        |                    |                        |
|                        |                    | Information Service,   |
|                        |                    | Springfield, VA 22161  |
|                        |                    |                        |
|                        |                    | This document is also  |
|                        |                    | available on           |
|                        |                    |                        |
|                        |                    | the FRA website at     |
|                        |                    | www.fra.dot.gov        |
+------------------------+--------------------+------------------------+

+-----------------------------------------------------------------------+
| > Notice                                                              |
|                                                                       |
| This document is disseminated under the sponsorship of the Department |
| of Transportation in the interest of information exchange. The United |
| States Government assumes no liability for its contents or use        |
| thereof.                                                              |
+-----------------------------------------------------------------------+
|                                                                       |
+-----------------------------------------------------------------------+
| > Notice                                                              |
|                                                                       |
| The United States Government does not endorse products or             |
| manufacturers. Trade or manufacturers' names appear herein solely     |
| because they are considered essential to the objective of this        |
| report.                                                               |
+-----------------------------------------------------------------------+

+------------------+---+--------------+---+-------+---+---+--------------+
| **Report         |   |              |   |       | F |   |              |
| Documentation    |   |              |   |       | o |   |              |
| page**           |   |              |   |       | r |   |              |
|                  |   |              |   |       | m |   |              |
|                  |   |              |   |       | A |   |              |
|                  |   |              |   |       | p |   |              |
|                  |   |              |   |       | p |   |              |
|                  |   |              |   |       | r |   |              |
|                  |   |              |   |       | o |   |              |
|                  |   |              |   |       | v |   |              |
|                  |   |              |   |       | e |   |              |
|                  |   |              |   |       | d |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       | O |   |              |
|                  |   |              |   |       | M |   |              |
|                  |   |              |   |       | B |   |              |
|                  |   |              |   |       | N |   |              |
|                  |   |              |   |       | o |   |              |
|                  |   |              |   |       | . |   |              |
|                  |   |              |   |       | 0 |   |              |
|                  |   |              |   |       | 7 |   |              |
|                  |   |              |   |       | 0 |   |              |
|                  |   |              |   |       | 4 |   |              |
|                  |   |              |   |       | - |   |              |
|                  |   |              |   |       | 0 |   |              |
|                  |   |              |   |       | 1 |   |              |
|                  |   |              |   |       | 8 |   |              |
|                  |   |              |   |       | 8 |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| Public reporting |   |              |   |       |   |   |              |
| burden for this  |   |              |   |       |   |   |              |
| collection of    |   |              |   |       |   |   |              |
| information is   |   |              |   |       |   |   |              |
| estimated to     |   |              |   |       |   |   |              |
| average 1 hour   |   |              |   |       |   |   |              |
| per response,    |   |              |   |       |   |   |              |
| including the    |   |              |   |       |   |   |              |
| time for         |   |              |   |       |   |   |              |
| reviewing        |   |              |   |       |   |   |              |
| instructions,    |   |              |   |       |   |   |              |
| searching        |   |              |   |       |   |   |              |
| existing data    |   |              |   |       |   |   |              |
| sources,         |   |              |   |       |   |   |              |
| gathering and    |   |              |   |       |   |   |              |
| maintaining the  |   |              |   |       |   |   |              |
| data needed and  |   |              |   |       |   |   |              |
| completing and   |   |              |   |       |   |   |              |
| reviewing the    |   |              |   |       |   |   |              |
| collection of    |   |              |   |       |   |   |              |
| information.     |   |              |   |       |   |   |              |
| Send comments    |   |              |   |       |   |   |              |
| regarding this   |   |              |   |       |   |   |              |
| burden estimate  |   |              |   |       |   |   |              |
| or any aspects   |   |              |   |       |   |   |              |
| of this          |   |              |   |       |   |   |              |
| collection of    |   |              |   |       |   |   |              |
| information ,    |   |              |   |       |   |   |              |
| including        |   |              |   |       |   |   |              |
| suggestions for  |   |              |   |       |   |   |              |
| reducing this    |   |              |   |       |   |   |              |
| burden to        |   |              |   |       |   |   |              |
| Washington       |   |              |   |       |   |   |              |
| Headquarters     |   |              |   |       |   |   |              |
| Service,         |   |              |   |       |   |   |              |
| Directorate for  |   |              |   |       |   |   |              |
| information      |   |              |   |       |   |   |              |
| Operations and   |   |              |   |       |   |   |              |
| Reports. 1215    |   |              |   |       |   |   |              |
| Jefferson Davis  |   |              |   |       |   |   |              |
| Highway, Suite   |   |              |   |       |   |   |              |
| 1204, Arlington, |   |              |   |       |   |   |              |
| VA. 222202-4302, |   |              |   |       |   |   |              |
| and to the       |   |              |   |       |   |   |              |
| Office of        |   |              |   |       |   |   |              |
| Management and   |   |              |   |       |   |   |              |
| Budget,          |   |              |   |       |   |   |              |
| Paperwork        |   |              |   |       |   |   |              |
| Reduction        |   |              |   |       |   |   |              |
| Project          |   |              |   |       |   |   |              |
| (0704-0188),     |   |              |   |       |   |   |              |
| Washington, DC   |   |              |   |       |   |   |              |
| 20503.           |   |              |   |       |   |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 1\. Agency Use   |   | 2.  Report   |   | 3.  R |   |   |              |
| Only (*Leave     |   |     Date     |   | EPORT |   |   |              |
| blank*)          |   |              |   |       |   |   |              |
|                  |   | July 2005    |   |  TYPE |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |   AND |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   | DATES |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |    CO |   |   |              |
|                  |   |              |   | VERED |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   | Final |   |   |              |
|                  |   |              |   | R     |   |   |              |
|                  |   |              |   | eport |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   | Sept  |   |   |              |
|                  |   |              |   | ember |   |   |              |
|                  |   |              |   | 1995  |   |   |              |
|                  |   |              |   | -June |   |   |              |
|                  |   |              |   | 1997  |   |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 4.  Title and    |   |              |   |       | 5 |   |              |
|     subtitle     |   |              |   |       | . |   |              |
|                  |   |              |   |       |   |   |              |
| Preview          |   |              |   |       |   |   |              |
| Information in   |   |              |   |       | F |   |              |
| Cab Displays for |   |              |   |       | U |   |              |
| High-Speed       |   |              |   |       | N |   |              |
| Locomotives      |   |              |   |       | D |   |              |
|                  |   |              |   |       | I |   |              |
|                  |   |              |   |       | N |   |              |
|                  |   |              |   |       | G |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       | N |   |              |
|                  |   |              |   |       | U |   |              |
|                  |   |              |   |       | M |   |              |
|                  |   |              |   |       | B |   |              |
|                  |   |              |   |       | E |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | S |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | 2 |   |              |
|                  |   |              |   |       | 1 |   |              |
|                  |   |              |   |       | 0 |   |              |
|                  |   |              |   |       | 3 |   |              |
|                  |   |              |   |       | / |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | 2 |   |              |
|                  |   |              |   |       | 0 |   |              |
|                  |   |              |   |       | 4 |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 6.  AUTHOR(S)    |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
| Jay Einhorn,     |   |              |   |       |   |   |              |
| Thomas Sheridan, |   |              |   |       |   |   |              |
| and Jordan       |   |              |   |       |   |   |              |
| Multer           |   |              |   |       |   |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 7.  PERFORMING   |   |              |   |       | 8 |   |              |
|     ORGANIZATION |   |              |   |       | . |   |              |
|     NAME(S) AND  |   |              |   |       |   |   |              |
|     ADDRESS(ES)  |   |              |   |       |   |   |              |
|                  |   |              |   |       | P |   |              |
| U.S. Department  |   |              |   |       | E |   |              |
| of               |   |              |   |       | R |   |              |
| Transportation\  |   |              |   |       | F |   |              |
| Research and     |   |              |   |       | O |   |              |
| Special Programs |   |              |   |       | R |   |              |
| Administration\  |   |              |   |       | M |   |              |
| John A. Volpe    |   |              |   |       | I |   |              |
| National         |   |              |   |       | N |   |              |
| Transportation   |   |              |   |       | G |   |              |
| Systems Center\  |   |              |   |       |   |   |              |
| Cambridge, MA    |   |              |   |       |   |   |              |
| 02142-1093       |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       | O |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | G |   |              |
|                  |   |              |   |       | A |   |              |
|                  |   |              |   |       | N |   |              |
|                  |   |              |   |       | I |   |              |
|                  |   |              |   |       | Z |   |              |
|                  |   |              |   |       | A |   |              |
|                  |   |              |   |       | T |   |              |
|                  |   |              |   |       | I |   |              |
|                  |   |              |   |       | O |   |              |
|                  |   |              |   |       | N |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       | D |   |              |
|                  |   |              |   |       | O |   |              |
|                  |   |              |   |       | T |   |              |
|                  |   |              |   |       | - |   |              |
|                  |   |              |   |       | V |   |              |
|                  |   |              |   |       | N |   |              |
|                  |   |              |   |       | T |   |              |
|                  |   |              |   |       | S |   |              |
|                  |   |              |   |       | C |   |              |
|                  |   |              |   |       | - |   |              |
|                  |   |              |   |       | F |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | A |   |              |
|                  |   |              |   |       | - |   |              |
|                  |   |              |   |       | 0 |   |              |
|                  |   |              |   |       | 4 |   |              |
|                  |   |              |   |       | - |   |              |
|                  |   |              |   |       | 0 |   |              |
|                  |   |              |   |       | 6 |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 9.  SPONS        |   |              |   |       | 1 |   |              |
| ORING/MONITORING |   |              |   |       | 0 |   |              |
|     AGENCY       |   |              |   |       | . |   |              |
|     NAME(S) AND  |   |              |   |       |   |   |              |
|     ADDRESS(ES)  |   |              |   |       | S |   |              |
|                  |   |              |   |       | P |   |              |
| U.S. Department  |   |              |   |       | O |   |              |
| of               |   |              |   |       | N |   |              |
| Transportation\  |   |              |   |       | S |   |              |
| Federal Railroad |   |              |   |       | O |   |              |
| Administration\  |   |              |   |       | R |   |              |
| Office of        |   |              |   |       | I |   |              |
| Research and     |   |              |   |       | N |   |              |
| Development Mail |   |              |   |       | G |   |              |
| Stop 20\         |   |              |   |       | / |   |              |
| 1120 Vermont     |   |              |   |       | M |   |              |
| Avenue, NW\      |   |              |   |       | O |   |              |
| Washington, DC   |   |              |   |       | N |   |              |
| 20590            |   |              |   |       | I |   |              |
|                  |   |              |   |       | T |   |              |
|                  |   |              |   |       | O |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | I |   |              |
|                  |   |              |   |       | N |   |              |
|                  |   |              |   |       | G |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       | A |   |              |
|                  |   |              |   |       | G |   |              |
|                  |   |              |   |       | E |   |              |
|                  |   |              |   |       | N |   |              |
|                  |   |              |   |       | C |   |              |
|                  |   |              |   |       | Y |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | E |   |              |
|                  |   |              |   |       | P |   |              |
|                  |   |              |   |       | O |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | T |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       | N |   |              |
|                  |   |              |   |       | U |   |              |
|                  |   |              |   |       | M |   |              |
|                  |   |              |   |       | B |   |              |
|                  |   |              |   |       | E |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       | D |   |              |
|                  |   |              |   |       | O |   |              |
|                  |   |              |   |       | T |   |              |
|                  |   |              |   |       | / |   |              |
|                  |   |              |   |       | F |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | A |   |              |
|                  |   |              |   |       | / |   |              |
|                  |   |              |   |       | O |   |              |
|                  |   |              |   |       | R |   |              |
|                  |   |              |   |       | D |   |              |
|                  |   |              |   |       | - |   |              |
|                  |   |              |   |       | 0 |   |              |
|                  |   |              |   |       | 4 |   |              |
|                  |   |              |   |       | / |   |              |
|                  |   |              |   |       | 1 |   |              |
|                  |   |              |   |       | 2 |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 1                |   |              |   |       |   |   |              |
| 1. SUPPLEMENTARY |   |              |   |       |   |   |              |
|     NOTES        |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
| Safety of        |   |              |   |       |   |   |              |
| High-Speed       |   |              |   |       |   |   |              |
| Ground           |   |              |   |       |   |   |              |
| Transportation   |   |              |   |       |   |   |              |
| Systems series   |   |              |   |       |   |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 12a.             |   |              |   |       | 1 |   |              |
| DISTRIBUT        |   |              |   |       | 2 |   |              |
| ION/AVAILABILITY |   |              |   |       | b |   |              |
| STATEMENT        |   |              |   |       | . |   |              |
|                  |   |              |   |       | D |   |              |
| This document is |   |              |   |       | I |   |              |
| available to the |   |              |   |       | S |   |              |
| public through   |   |              |   |       | T |   |              |
| the National     |   |              |   |       | R |   |              |
| Technical        |   |              |   |       | I |   |              |
| Information      |   |              |   |       | B |   |              |
| Service,         |   |              |   |       | U |   |              |
| Springfield,     |   |              |   |       | T |   |              |
| Virginia 22161.  |   |              |   |       | I |   |              |
| This document is |   |              |   |       | O |   |              |
| also available   |   |              |   |       | N |   |              |
| on the FRA web   |   |              |   |       | C |   |              |
| site at          |   |              |   |       | O |   |              |
| www.fra.dot.gov. |   |              |   |       | D |   |              |
|                  |   |              |   |       | E |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 13. ABSTRACT     |   |              |   |       |   |   |              |
|     (Maximum 200 |   |              |   |       |   |   |              |
|     words)       |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
| This research    |   |              |   |       |   |   |              |
| examined the     |   |              |   |       |   |   |              |
| usefulness of    |   |              |   |       |   |   |              |
| preview          |   |              |   |       |   |   |              |
| information in   |   |              |   |       |   |   |              |
| the control of   |   |              |   |       |   |   |              |
| high-speed       |   |              |   |       |   |   |              |
| trains.          |   |              |   |       |   |   |              |
| Experiments were |   |              |   |       |   |   |              |
| run on a         |   |              |   |       |   |   |              |
| h                |   |              |   |       |   |   |              |
| uman-in-the-loop |   |              |   |       |   |   |              |
| locomotive       |   |              |   |       |   |   |              |
| simulator. The   |   |              |   |       |   |   |              |
| primary goal was |   |              |   |       |   |   |              |
| to examine       |   |              |   |       |   |   |              |
| whether the      |   |              |   |       |   |   |              |
| proposed         |   |              |   |       |   |   |              |
| in               |   |              |   |       |   |   |              |
| formation-aiding |   |              |   |       |   |   |              |
| displays         |   |              |   |       |   |   |              |
| improved safety  |   |              |   |       |   |   |              |
| and efficiency   |   |              |   |       |   |   |              |
| of train         |   |              |   |       |   |   |              |
| operation over   |   |              |   |       |   |   |              |
| an existing      |   |              |   |       |   |   |              |
| display. Safety  |   |              |   |       |   |   |              |
| was measured by  |   |              |   |       |   |   |              |
| monitoring speed |   |              |   |       |   |   |              |
| control, signal  |   |              |   |       |   |   |              |
| adherence, and   |   |              |   |       |   |   |              |
| reaction time.   |   |              |   |       |   |   |              |
| Efficiency was   |   |              |   |       |   |   |              |
| measured by      |   |              |   |       |   |   |              |
| monitoring       |   |              |   |       |   |   |              |
| stopping         |   |              |   |       |   |   |              |
| accuracy and     |   |              |   |       |   |   |              |
| schedule         |   |              |   |       |   |   |              |
| deviation.       |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
| Locomotive       |   |              |   |       |   |   |              |
| engineers and    |   |              |   |       |   |   |              |
| student          |   |              |   |       |   |   |              |
| participants     |   |              |   |       |   |   |              |
| performed        |   |              |   |       |   |   |              |
| similarly with   |   |              |   |       |   |   |              |
| respect to       |   |              |   |       |   |   |              |
| signal adherence |   |              |   |       |   |   |              |
| and speed        |   |              |   |       |   |   |              |
| control. Preview |   |              |   |       |   |   |              |
| information was  |   |              |   |       |   |   |              |
| useful in both   |   |              |   |       |   |   |              |
| cases; Longer    |   |              |   |       |   |   |              |
| preview and      |   |              |   |       |   |   |              |
| variable preview |   |              |   |       |   |   |              |
| displays         |   |              |   |       |   |   |              |
| provided the     |   |              |   |       |   |   |              |
| best results.    |   |              |   |       |   |   |              |
| The preview      |   |              |   |       |   |   |              |
| displays were    |   |              |   |       |   |   |              |
| detrimental to   |   |              |   |       |   |   |              |
| accurate         |   |              |   |       |   |   |              |
| s                |   |              |   |       |   |   |              |
| tation-stopping, |   |              |   |       |   |   |              |
| as the displays  |   |              |   |       |   |   |              |
| provided an      |   |              |   |       |   |   |              |
| inadequate level |   |              |   |       |   |   |              |
| of resolution to |   |              |   |       |   |   |              |
| stop accurately. |   |              |   |       |   |   |              |
| Although the     |   |              |   |       |   |   |              |
| locomotive       |   |              |   |       |   |   |              |
| engineers        |   |              |   |       |   |   |              |
| responded        |   |              |   |       |   |   |              |
| favorably to the |   |              |   |       |   |   |              |
| preview          |   |              |   |       |   |   |              |
| displays,        |   |              |   |       |   |   |              |
| further work is  |   |              |   |       |   |   |              |
| needed to        |   |              |   |       |   |   |              |
| determine how    |   |              |   |       |   |   |              |
| the engineer     |   |              |   |       |   |   |              |
| allocates        |   |              |   |       |   |   |              |
| attention        |   |              |   |       |   |   |              |
| between          |   |              |   |       |   |   |              |
| information in   |   |              |   |       |   |   |              |
| the cab and      |   |              |   |       |   |   |              |
| information      |   |              |   |       |   |   |              |
| outside the cab. |   |              |   |       |   |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 14. SUBJECT      |   |              |   |       |   | 1 |              |
|     TERMS        |   |              |   |       |   | 5 |              |
|                  |   |              |   |       |   | . |              |
|     attention    |   |              |   |       |   |   |              |
|     allocation,  |   |              |   |       |   | N |              |
|     automation,  |   |              |   |       |   | U |              |
|     high-speed   |   |              |   |       |   | M |              |
|     trains,      |   |              |   |       |   | B |              |
|     h            |   |              |   |       |   | E |              |
| uman-in-the-loop |   |              |   |       |   | R |              |
|     simulation,  |   |              |   |       |   |   |              |
|     intelligent  |   |              |   |       |   |   |              |
|     railroad     |   |              |   |       |   |   |              |
|     systems,     |   |              |   |       |   |   |              |
|     situation    |   |              |   |       |   | O |              |
|     awareness,   |   |              |   |       |   | F |              |
|     supervisory  |   |              |   |       |   |   |              |
|     control      |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   | P |              |
|                  |   |              |   |       |   | A |              |
|                  |   |              |   |       |   | G |              |
|                  |   |              |   |       |   | E |              |
|                  |   |              |   |       |   | S |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   | 6 |              |
|                  |   |              |   |       |   | 0 |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   | 1 |              |
|                  |   |              |   |       |   | 6 |              |
|                  |   |              |   |       |   | . |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   | P |              |
|                  |   |              |   |       |   | R |              |
|                  |   |              |   |       |   | I |              |
|                  |   |              |   |       |   | C |              |
|                  |   |              |   |       |   | E |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   | C |              |
|                  |   |              |   |       |   | O |              |
|                  |   |              |   |       |   | D |              |
|                  |   |              |   |       |   | E |              |
+------------------+---+--------------+---+-------+---+---+--------------+
| 17. SECURITY     | 1 |              | 1 |       |   |   | 20           |
|                  | 8 |              | 9 |       |   |   | . LIMITATION |
|   CLASSIFICATION | . |              | . |       |   |   |     OF       |
|     OF REPORT    |   |              |   |       |   |   |     ABSTRACT |
|                  | S |              | S |       |   |   |              |
|     Unclassified | E |              | E |       |   |   |              |
|                  | C |              | C |       |   |   |              |
|                  | U |              | U |       |   |   |              |
|                  | R |              | R |       |   |   |              |
|                  | I |              | I |       |   |   |              |
|                  | T |              | T |       |   |   |              |
|                  | Y |              | Y |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  | C |              | C |       |   |   |              |
|                  | L |              | L |       |   |   |              |
|                  | A |              | A |       |   |   |              |
|                  | S |              | S |       |   |   |              |
|                  | S |              | S |       |   |   |              |
|                  | I |              | I |       |   |   |              |
|                  | F |              | F |       |   |   |              |
|                  | I |              | I |       |   |   |              |
|                  | C |              | C |       |   |   |              |
|                  | A |              | A |       |   |   |              |
|                  | T |              | T |       |   |   |              |
|                  | I |              | I |       |   |   |              |
|                  | O |              | O |       |   |   |              |
|                  | N |              | N |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  | O |              | O |       |   |   |              |
|                  | F |              | F |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  | T |              | A |       |   |   |              |
|                  | H |              | B |       |   |   |              |
|                  | I |              | S |       |   |   |              |
|                  | S |              | T |       |   |   |              |
|                  |   |              | R |       |   |   |              |
|                  |   |              | A |       |   |   |              |
|                  |   |              | C |       |   |   |              |
|                  |   |              | T |       |   |   |              |
|                  | P |              |   |       |   |   |              |
|                  | A |              |   |       |   |   |              |
|                  | G |              |   |       |   |   |              |
|                  | E |              |   |       |   |   |              |
|                  |   |              |   |       |   |   |              |
|                  |   |              | U |       |   |   |              |
|                  |   |              | n |       |   |   |              |
|                  |   |              | c |       |   |   |              |
|                  |   |              | l |       |   |   |              |
|                  | U |              | a |       |   |   |              |
|                  | n |              | s |       |   |   |              |
|                  | c |              | s |       |   |   |              |
|                  | l |              | i |       |   |   |              |
|                  | a |              | f |       |   |   |              |
|                  | s |              | i |       |   |   |              |
|                  | s |              | e |       |   |   |              |
|                  | i |              | d |       |   |   |              |
|                  | f |              |   |       |   |   |              |
|                  | i |              |   |       |   |   |              |
|                  | e |              |   |       |   |   |              |
|                  | d |              |   |       |   |   |              |
+------------------+---+--------------+---+-------+---+---+--------------+

METRIC/ENGLISH CONVERSION FACTORS

<table style="width:100%;">
<colgroup>
<col style="width: 23%" />
<col style="width: 1%" />
<col style="width: 0%" />
<col style="width: 23%" />
<col style="width: 0%" />
<col style="width: 23%" />
<col style="width: 0%" />
<col style="width: 1%" />
<col style="width: 0%" />
<col style="width: 0%" />
<col style="width: 24%" />
</colgroup>
<thead>
<tr class="header">
<th colspan="5"><strong>ENGLISH TO METRIC</strong></th>
<th colspan="6"><strong>METRIC TO ENGLISH</strong></th>
</tr>
<tr class="odd">
<th colspan="5"><strong>LENGTH (APPROXIMATE)</strong></th>
<th colspan="6"><strong>LENGTH (APPROXIMATE)</strong></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td><strong>1 inch (in)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>2.5 centimeters (cm)</strong></td>
<td colspan="2"><strong>1 millimeter (mm)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.04 inch (in)</strong></td>
</tr>
<tr class="even">
<td><strong>1 foot (ft)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>30 centimeters (cm)</strong></td>
<td colspan="2"><strong>1 centimeter (cm)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.4 inch (in)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 yard (yd)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.9 meter (m)</strong></td>
<td colspan="2"><strong>1 meter (m)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>3.3 feet (ft)</strong></td>
</tr>
<tr class="even">
<td><strong>1 mile (mi)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>1.6 kilometers (km)</strong></td>
<td colspan="2"><strong>1 meter (m)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>1.1 yards (yd)</strong></td>
</tr>
<tr class="odd">
<td></td>
<td></td>
<td colspan="2"></td>
<td colspan="2"><strong>1 kilometer (km)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.6 mile (mi)</strong></td>
</tr>
<tr class="even">
<td colspan="5"><strong>AREA (APPROXIMATE)</strong></td>
<td colspan="6"><strong>AREA (APPROXIMATE)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 square inch (sq in, in<sup>2</sup>)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>6.5 square centimeters
(cm<sup>2</sup>)</strong></td>
<td colspan="2"><strong>1 square centimeter
(cm<sup>2</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.16 square inch (sq in,
in<sup>2</sup>)</strong></td>
</tr>
<tr class="even">
<td><strong>1 square foot (sq ft, ft<sup>2</sup>)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.09 square meter (m<sup>2</sup>)</strong></td>
<td colspan="2"><strong>1 square meter (m<sup>2</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>1.2 square yards (sq yd,
yd<sup>2</sup>)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 square yard (sq yd, yd<sup>2</sup>)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.8 square meter (m<sup>2</sup>)</strong></td>
<td colspan="2"><strong>1 square kilometer
(km<sup>2</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>0.4 square mile (sq mi,
mi<sup>2</sup>)</strong></td>
</tr>
<tr class="even">
<td><strong>1 square mile (sq mi, mi<sup>2</sup>)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>2.6 square kilometers
(km<sup>2</sup>)</strong></td>
<td colspan="2"><strong>10,000 square meters
(m<sup>2</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td colspan="2"><strong>1 hectare (ha) = 2.5 acres</strong></td>
</tr>
<tr class="odd">
<td><strong>1 acre = 0.4 hectare (he)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>4,000 square meters
(m<sup>2</sup>)</strong></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td colspan="2"></td>
</tr>
<tr class="even">
<td colspan="5"><strong>MASS - WEIGHT (APPROXIMATE)</strong></td>
<td colspan="6"><strong>MASS - WEIGHT (APPROXIMATE)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 ounce (oz)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>28 grams (gm)</strong></td>
<td colspan="2"><strong>1 gram (gm)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="3"><strong>0.036 ounce (oz)</strong></td>
</tr>
<tr class="even">
<td><strong>1 pound (lb)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.45 kilogram (kg)</strong></td>
<td colspan="2"><strong>1 kilogram (kg)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="3"><strong>2.2 pounds (lb)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 short ton = 2,000 pounds (lb)</strong></td>
<td><strong>=</strong></td>
<td colspan="2"><strong>0.9 tonne (t)</strong></td>
<td colspan="2"><strong>1 tonne (t)</strong></td>
<td colspan="2"><p><strong>=</strong></p>
<p><strong>=</strong></p></td>
<td colspan="3"><p><strong>1,000 kilograms (kg)</strong></p>
<p><strong>1.1 short tons</strong></p></td>
</tr>
<tr class="even">
<td colspan="5"><strong>VOLUME (APPROXIMATE)</strong></td>
<td colspan="6"><strong>VOLUME (APPROXIMATE)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 teaspoon (tsp)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>5 milliliters (ml)</strong></td>
<td colspan="2"><strong>1 milliliter (ml)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>0.03 fluid ounce (fl oz)</strong></td>
</tr>
<tr class="even">
<td><strong>1 tablespoon (tbsp)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>15 milliliters (ml)</strong></td>
<td colspan="2"><strong>1 liter (l)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>2.1 pints (pt)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 fluid ounce (fl oz)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>30 milliliters (ml)</strong></td>
<td colspan="2"><strong>1 liter (l)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>1.06 quarts (qt)</strong></td>
</tr>
<tr class="even">
<td><strong>1 cup (c)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.24 liter (l)</strong></td>
<td colspan="2"><strong>1 liter (l)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>0.26 gallon (gal)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 pint (pt)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.47 liter (l)</strong></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td><strong>1 quart (qt)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.96 liter (l)</strong></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="odd">
<td><strong>1 gallon (gal)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>3.8 liters (l)</strong></td>
<td colspan="2"></td>
<td colspan="3"></td>
<td></td>
</tr>
<tr class="even">
<td><strong>1 cubic foot (cu ft, ft<sup>3</sup>)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.03 cubic meter (m<sup>3</sup>)</strong></td>
<td colspan="2"><strong>1 cubic meter (m<sup>3</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>36 cubic feet (cu ft, ft<sup>3</sup>)</strong></td>
</tr>
<tr class="odd">
<td><strong>1 cubic yard (cu yd, yd<sup>3</sup>)</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>0.76 cubic meter (m<sup>3</sup>)</strong></td>
<td colspan="2"><strong>1 cubic meter (m<sup>3</sup>)</strong></td>
<td colspan="3"><strong>=</strong></td>
<td><strong>1.3 cubic yards (cu yd, yd<sup>3</sup>)</strong></td>
</tr>
<tr class="even">
<td colspan="5"><strong>TEMPERATURE (EXACT)</strong></td>
<td colspan="6"><strong>TEMPERATURE (EXACT)</strong></td>
</tr>
<tr class="odd">
<td><strong>[(x-32)(5/9)] F</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>y C</strong></td>
<td colspan="2"><strong>[(9/5) y + 32] C</strong></td>
<td colspan="2"><strong>=</strong></td>
<td colspan="2"><strong>x F</strong></td>
</tr>
</tbody>
</table>

![](media/image4.wmf)

![](media/image5.wmf)

For more exact and or other conversion factors, see NIST Miscellaneous
Publication 286, Units of Weights and Measures. Price \$2.50 SD Catalog
No. C13 10286

# PREFACE {#preface .Contents-1-no-show}

This research was performed as part of an ongoing program at the U. S.
Department of Transportation\'s John A. Volpe National Transportation
Systems Center (Volpe Center) in collaboration with the Human-Machine
Systems Laboratory (HMSL) of the Massachusetts Institute of Technology
(MIT). The Federal Railroad Administration's (FRA) Office of Research
and Development sponsored this study as part of its effort to support
the safe and efficient operation of high-speed ground transportation.

As vehicle speed increases, the limits of human information processing
remains fixed. High speeds increase the processing demand per unit time
on the locomotive engineer, while also decreasing the available response
time. One approach to this dilemma is to give the locomotive engineer
information about the status of the upcoming track earlier in time. This
report addresses whether preview information is helpful with regard to
safe and efficient train operations.

# ACKNOWLEDGMENTS {#acknowledgments .Contents-1-no-show}

This report is the result of many people's labor. We would like to thank
Kari Kulaszewicz for her help and good nature; Steven Villareal for his
help with the sound generation and the building of the locomotive cab;
John Pollard for his help with many different aspects of the simulation,
and Frank Sheelen for his technical expertise. Dr. Ed Lanzilotta wrote
much of the code that the MIT/Volpe locomotive simulator is based on,
and his guidance and effort will serve as a reminder of how people of
faith and wisdom should act.

Many people from the railroads and locomotive manufacturers shared their
knowledge and frank opinions with us. We thank Masahiko Horiuchi of East
Japan Railway Company; Dick Bruss, Ron Berben, and Pat Kelley of Amtrak;
Daniel Metaut and Philippe Mingasson of Alsthom; Bengt Lindwall of
AdTranz; Howard Moody of the Association of American Railroads; and
George Kuehn of the Illinois Institute of Technology Research Institute.

I would particularly like to acknowledge Steven Jones and Joe Arcuri of
Amtrak for their help in finding locomotive engineers to participate.
The participants themselves are owed a deep debt of gratitude for giving
up their days off to help us with our work.

The Federal Railroad Administration sponsored this work as part of its
activities to develop Intelligent Railroad Systems (Federal Railroad
Administration, 2002).

# LIST OF ACRONYMS {#list-of-acronyms .Contents-1-no-show}

AAR -- Association of American Railroads

ARES -- Advanced Railroad Electronics System

ATC -- Automatic Train Control

ATCS -- Advanced Train Control System

ATP -- Automatic Train Protection

BN -- Burlington Northern Railroad (predecessor to BNSF)

BNSF -- Burlington Northern Santa Fe Railroad

CIR -- Computer Integrated Railroading

DB -- Deutsche Bahn (German Railways)

FRA -- Federal Railroad Administration

GE -- General Electric

GM -- General Motors

HMSL -- Human-Machine Systems Laboratory

ICE -- Inter-City Express

ITCS -- Incremental Train Control System

JR -- Japan Rail

MIT -- Massachusetts Institute of Technology

OTW -- Out-The-Window

PSI -- Pounds per Square Inch

PTS -- Positive Train Separation

RAC -- Railway Association of Canada

SJ -- Statens Jarnvager (Swedish State Railways)

SNCF -- Société Nationale des Chemins de Fer Français (French National
Railways)

TGV -- Train à Grande Vitesse

UP -- United Pacific Railroad

Volpe Center -- John A. Volpe National Transportation Systems Center

# TABLE OF CONTENTS {#table-of-contents .Contents-1-no-show}

**[Section]{.underline}** **[Page]{.underline}**

[EXECUTIVE SUMMARY ix](#executive-summary)

[1. INTRODUCTION 1](#introduction-1)

[1.1 Research Goals 2](#research-goals)

[2. LOCOMOTIVE CAB DISPLAYS IN HIGH-SPEED OPERATIONS
3](#locomotive-cab-displays-in-high-speed-operations)

[2.1 Sweden 3](#sweden)

[2.2 Japan 5](#japan)

[2.3 France 7](#france)

[2.4 Germany 8](#germany)

[2.5 North American Railroads 9](#north-american-railroads)

[2.6 Amtrak 11](#amtrak)

[2.7 Summary 12](#summary)

[3. SIMULATOR EXPERIMENT 15](#simulator-experiment)

[3.1 Overview 15](#overview)

[3.2 Locomotive Simulator 15](#locomotive-simulator)

[3.3 Experimental Design 16](#experimental-design)

[3.4 Task 20](#task)

[3.5 Participants 21](#participants)

[3.6 Training 21](#training)

[4. RESULTS AND DISCUSSION 23](#results-and-discussion-1)

[4.1 Speed Control 23](#speed-control-1)

[4.2 Signal Adherence 23](#signal-adherence-1)

[4.3 Brake Response Latency 25](#brake-response-latency)

[4.4 Schedule Deviation 25](#schedule-deviation-1)

[4.5 Station-Stopping Accuracy 26](#station-stopping-accuracy-1)

[4.6 Comparison Between Engineers and Students
27](#comparison-between-engineers-and-students)

[5. SUMMARY 29](#summary-1)

[APPENDIX A: TRAIN SCHEDULE 33](#appendix-a-train-schedule)

[APPENDIX B: EXIT QUESTIONNAIRE 35](#appendix-b-exit-questionnaire)

[APPENDIX C: FUTURE LOCOMOTIVE SIMULATOR CONSIDERATIONS
37](#appendix-c-future-locomotive-simulator-considerations)

[GLOSSARY 43](#glossary)

[REFERENCES 45](#references)

# LIST OF FIGURES {#list-of-figures .Contents-1-no-show}

**[Figure]{.underline} [Page]{.underline}**

1\. X2000 Instrument Panel [4](#__RefHeading___Toc511535070)

2\. X2000 Fault Indication Panel [4](#__RefHeading___Toc511535071)

3\. Shinkansen MON4 Display [6](#__RefHeading___Toc511535072)

4\. Shinkansen MON10 Display [6](#__RefHeading___Toc511535073)

5\. Interior of a TGV-PBKA Cab [7](#__RefHeading___Toc511535074)

6\. ASTREE Cab Display (de Curzon, 1994)
[8](#__RefHeading___Toc511535075)

7\. Interior of an ICE Cab [9](#__RefHeading___Toc511535076)

8\. AAR LSI (Train Control) Display [10](#__RefHeading___Toc511535077)

9\. AAR ATCS (Track/Authority) Display
[11](#__RefHeading___Toc511535078)

10\. GE/Amtrak Genesis II Gauge Display
[12](#__RefHeading___Toc511535079)

11\. Simulated Locomotive Cab [16](#__RefHeading___Toc511535080)

12\. Genesis II Locomotive Display [17](#__RefHeading___Toc511535081)

13\. Preview Display [18](#__RefHeading___Toc511535082)

# LIST OF TABLES {#list-of-tables .Contents-1-no-show}

**[Table]{.underline} [Page]{.underline}**

Table 1. Askey\'s Display-Aiding Levels
[1](#__RefHeading___Toc513625141)

Table 2. Shinkansen Power Car Characteristics
[5](#__RefHeading___Toc513625142)

Table 3. Independent Variables [19](#__RefHeading___Toc513625143)

Table 4. Operating Disturbances [20](#__RefHeading___Toc513625144)

Table 5. Frequency of Speed Violations by Display Condition
[23](#__RefHeading___Toc513625145)

Table 6. Signal Adherence by Preview Condition
[24](#__RefHeading___Toc513625146)

Table 7. Stop Signal Overruns [25](#__RefHeading___Toc513625147)

Table 8. Mean Braking Response Latency(s) to Restricted Signal
[25](#__RefHeading___Toc513625148)

Table 9. Schedule Deviation by Display Number for Trips without a Signal
Change [26](#__RefHeading___Toc513625149)

Table 10. Mean Station-Stopping Accuracy (ft) by Group
[27](#__RefHeading___Toc513625150)

Table 11. Mean Brake Response Time (s) by Group
[28](#__RefHeading___Toc513625151)

# EXECUTIVE SUMMARY {#executive-summary .Appendix-1}

## Introduction {#introduction .Appendix-2}

High speeds increase the processing demand per unit time on the
locomotive engineer, while also decreasing the available response time.
Increasing train speed reduces the time available for the engineer to
adjust train speed in anticipation of the upcoming track conditions. As
trains travel faster, locomotive engineers must process more information
in less time. Providing information far enough in advance to process and
take action may enable the locomotive engineer to more safely operate
the train at speeds above 79 mph. Traditionally, the locomotive engineer
obtained visual information for making train control decisions by
looking out the window. When available, wayside signals indicate whether
the train can enter a block and indicate whether the train can operate
at maximum speed authorized for that track section or whether it must
operate at lower speed. When operating at high speeds, the locomotive
engineer may not have sufficient time to brake after identifying the
signal. One answer is to display this information in the locomotive cab.
In the United States, trains traveling above 79 mph must display signals
in the cab.

Information about the status of the track some distance ahead of the
train is expected to aid locomotive engineers by partially compensating
for the decreased signal processing time imposed by higher train speeds
(above 79 mph). Such preview information may include the signal speed,
the civil speed, track occupancy, and braking characteristics. Both
Kuehn (1992) and Askey (1995) demonstrated that displays incorporating
preview information increased safety and efficiency of train operation.
The Advanced Train Control System (ATCS) guideline for preview
information was based upon discussions with engineers. The current study
seeks to answer the question, "How does preview distance affect
locomotive engineer train handling performance?"

The current research seeks to build on this knowledge regarding "preview
information" by specifically examining the length of preview on
locomotive engineer performance. This information was included in an
experimental display. This display was compared to the Genesis II
display used in Amtrak locomotives. The Genesis II display shows in-cab
signals, but does not provide preview information.

Prior to the development of a preview display, the development of train
control systems and locomotive cab displays in countries with high-speed
operations were reviewed. Based on this information, along with
interviews with locomotive engineers, locomotive manufacturers, and
railroads, a preview decision aid was developed and tested.

The literature review uncovered a wide variety of cab display paradigms
used in the countries operating high-speed trains. The differences that
exist include many important aspects of train control and cab display
design. For instance, Japanese engineers favor linear speedometers,
while American engineers favor circular speedometers. Each country has
its own convention regarding how train control information (speed,
traction and braking) is displayed. This raises the question, "To what
extent does the way train control information is displayed (e.g.,
horizontal versus vertical, linear versus circular, etc.) affect how the
engineer operates the train?" There also seems to be consensus among the
railroads in the various countries operating trains at high speeds that
the engineer needs information over and above the current block signal.

This experiment examined the differences in safety and efficiency of
train operation that might arise by using displays with and without
preview information. Information that is helpful to the engineer may
include upcoming speed restrictions, location and velocity of nearby
traffic, and upcoming distance cues (such as mileposts). This
information was included in an experimental display. This display was
compared to the Genesis II display used in Amtrak locomotives, a display
that offers no preview information. The Genesis II display shows signals
in the cab, but does not provide preview information.

To investigate these questions, an experiment was run on a
human-in-the-loop locomotive simulator, using locomotive engineers and
students. A second goal of the research was to compare the performance
of engineers and non-engineers. Previous studies using the locomotive
simulator were conducted using only students as participants. Can the
results of these studies be applied to locomotive engineers? Evaluating
performance for both groups allowed us to better understand the benefits
and limitations of using students in a job that requires a high level of
training to become proficient.

## Method {#method .Appendix-2}

The independent variables manipulated were preview distance and
participant type. Two displays were used to show the different preview
distances. This baseline display showed only the current block signal
(no preview information) in the form of a location-coded signal and
digital readouts of the civil and signal speed limits. There were three
preview conditions: 1.4 mile, 3.4 mile, and variable preview. The
preview display conditions were all variations of one experimental
display that showed the same brake, traction, and warning information as
the Genesis II display, but also contains speed-by-distance and traffic
preview information.

The large window in the middle of the preview display showed the
upcoming speed restrictions. If the white horizontal bar indicating the
train's current location was above the red line, the train was violating
the effective speed limit. Mileposts, switches, and stations were
indicated just below the speed preview window, above the track preview
display (described below). The preview displays also displayed
predictive full-service and emergency braking curves.

The following dependent measures were used to evaluate operator
performance: speed control, signal adherence, brake reaction time
latency, schedule deviation, and station-stopping accuracy. Speed
control was monitored by collecting data on the train speed relative to
the allowed speed. Locomotive engineers were expected to keep their
trains within a certain range of acceptable values. Signal adherence was
measured by recording whether the participant violated a signal (i.e.,
running past a red "stop" signal or passing a signal at a speed higher
than permitted). Brake reaction time latency to failure scenarios (i.e.,
a car stuck in a grade crossing or a dropped signal) was monitored by
recording reaction times to take action in response to a "failure" event
(i.e., the distance between the train and the event, such as a signal or
a car stuck in a crossing). Schedule deviation was measured by the
difference between the expected arrival time at each station and the
actual arrival time at each station. Station-stopping accuracy was
measured by comparing the participant's actual stopping location at each
station relative to a pre-defined mark (the end of each station
platform).

Three Amtrak locomotive engineers and six MIT students participated in
this experiment. Each participant operated the locomotive simulator on a
section of track modeled after a trip from South Station in Boston,
Massachusetts to Attleboro, Massachusetts. The participant's task was to
operate the train, given the schedule constraints and operating
conditions. The participant encountered a variety of disturbances such
as unexpected signals, speed restrictions, and moving to a siding to
allow another train to pass.

## Results and Discussion {#results-and-discussion .Appendix-2}

In this study, the preview displays improved performance on tasks where
the locomotive engineer's train control actions were made in advance of
the visual information needed to support those actions. Routine speed
control improved with the preview displays, although it was unclear
whether this difference would exist for the locomotive engineers if they
were more familiar with the territory and the train's dynamics. The
largest number of speed violations occurred in the no-preview display
condition.

The number of signal overruns decreased with preview information
compared to the no-preview condition. Among the preview displays,
participants demonstrated an easier time making control decision in the
variable preview condition. They exhibited the best braking performance
using the variable preview display, when exposed to an expected (static)
or unexpected (dynamic) signal. Participants using the 1.4-mile fixed
preview display performed better when faced with an expected signal than
when using the 3.4-mile fixed preview display. When faced with an
unexpected signal, the opposite result occurred. Participants performed
better using the 3.4-mile preview display than the 1.4-mile preview
display.

Braking response time also improved with the preview information,
particularly with the variable preview display. Response latencies were
shorter with the preview displays than the no-preview condition.
Participants performed best with the variable preview display followed
by the 1.4-mile display and the 3.4-mile display. The response latency
was considerably shorter for the variable display and the 1.4-mile
display conditions.

Preview information did not seem to support station-stopping accuracy.
However, participants also reported more problems using the preview
displays for station-stopping, particularly the variable preview
display.

Qualitative data from this study supports the quantitative data that
long preview or preview that scales with speed (offering greater
resolution at lower speeds) is preferable. When asked what preview
distance would make the job easiest, most of the participants responded
"as much as possible" or referred to either the 3.4-mile fixed preview
or the variable preview, while one engineer responded "5 to 10 miles."

The Amtrak engineers reacted favorably to the preview displays,
particularly since they "helped learn the territory." It is unclear
whether the engineers would have found the preview displays as useful if
they already knew the territory and the train's dynamics. In low
visibility conditions where locomotive engineers cannot rely on the
normal visual cues, a preview display may prove beneficial. One engineer
responded, "No preview is needed if you know the physical
characteristics \[of the train and track\]."

In designing such information aids, particular attention needs to be
paid to the engineer's strategies for allocating attention. The
engineers who operated the locomotive simulator liked the preview
displays and performed well with them. One engineer indicated that the
preview displays aided navigation in unfamiliar territory and was useful
to see the rate of deceleration relative to distance.

However, two of the engineers stressed their need to focus attention out
the window. One engineer complained about the amount of "electronic
harassment" in modern locomotive cabs precluding engineers from focusing
their attention out the window. That engineer said that the engineer's
attention is not necessarily needed to brake in time for a potential
emergency, but rather to be able to blow the horn in time in such a
case, or to accurately control the train when approaching a station
platform. In fact, this participant related that many engineers "cut
out" (turn off) the cab signaling and Automatic Train Protection (ATP)
in low-speed territory to remove the "distraction" of the warnings and
focus their attention on very fine control of the train's speed.
However, the danger is that they forget to cut it back in when they
return to high-speed territory.

With regard to station stopping accuracy, there was evidence that the
preview displays adversely affected performance, due to the lack of
resolution at lower speeds. The best information to support station
stopping is to look out the window. To aid station stopping, the preview
display needs to show enough detail for a locomotive engineer to
properly judge stopping distance.

Research is needed with regard to how this change of resolution should
take place (e.g., continuously or discretely). One way to investigate
this question is to allow the engineer to control the preview distance
and record what is chosen as a function of speed. Future work should
focus on how locomotive engineers allocate their attention, and on how
to effectively incorporate decision aids and training for those aids
into that attention allocation scheme.

The data indicate that the student and engineer groups exhibited similar
behavior in a relatively limited range of conditions. The two groups
exhibited similar behavior towards signal adherence and speed control.
However, the engineers appeared to focus their attention outside the
cab, which kept them from making full use of the preview display. This
was supported by the engineers' assertions that they need to focus their
attention out the window. This data suggests that previous experiments
using students as participants may give similar results using locomotive
engineers under two conditions: When locomotive engineers are
inexperienced and when the visual information engineers rely upon to
make decisions is impoverished. Otherwise, the training and operating
experience of experienced locomotive engineers results in behavior that
differs from those of students and others who lack this experience.

# INTRODUCTION

Trains, like ships, possess a considerable amount of inertia. There is a
relatively long lag between when a locomotive engineer initiates a
change in speed and that change affects the speed of the locomotive,
compared to motor vehicles and airplanes. An engineer must respond to
visual cues in the environment far in advance to safely operate a
locomotive. These visual cues include a variety of track conditions such
as grade, curvature, and track classification. Some of these cues are
permanent features of the environment; others are temporary. Locomotive
engineers spend considerable time learning the features of the territory
over which they will operate before they are certified to operate on
that territory. Increasing train speed reduces the time available for
the engineer to adjust train speed in anticipation of the upcoming track
conditions. In some territories, signals along the track indicate that a
train may move at the maximum authorized speed over that section.

As trains travel faster, locomotive engineers must process more
information in less time. At some point, the rate at which information
needs to be processed exceeds the engineer's abilities to respond in
time. This limitation is reached sooner if information is displayed in a
way that is difficult to access or understand. Providing information far
enough in advance to process and take action may enable the locomotive
engineer to more safely operate the train at speeds above 79 mph.
Traditionally, the locomotive engineer obtained visual information for
making train control decisions by looking out the window. From many
years of operating experience, the engineer used landmarks along the
territory to determine braking points. When available, wayside signals
indicate whether the train can enter a block and indicate the speed
limit. When operating at high speeds, the locomotive engineer may not
have sufficient time to brake after identifying the signal. One answer
is to display this information in the locomotive cab. In the United
States, trains traveling above 79 mph must display signals in the cab.

Askey (1995) examined the effects of providing varying levels of
information to the locomotive engineer on operator awareness, safety,
and efficiency. This study examined whether this information overloads
the operator to the point where the operator cannot react to an
unexpected scenario or perform a secondary task in an acceptable manner.
Askey created three decision aids that varied in the level of
information, as described in Table 1. Performance improved with
increasing levels of display aiding for the following measures:
station-stopping accuracy, schedule adherence, and reaction time to
unexpected signal changes. Moreover, the participants rated the most
complex display as imposing the lowest overall workload and preferred it
to any of the lower-level aiding displays.

  --------------------------------- ---------------- ------------------- -----------------------
  []{#__RefHeading___Toc513625141                                        
  .anchor}Table 1. Askey's                                               
  Display-Aiding Levels                                                  

  **Basic**                         **Preview**      **Predictor**       **Advisor**

  Current- and next-block signals   Effective speed  Maximum service and Advises on the optimal
                                    limit            emergency braking   speed trajectory to
                                    information for  curves, along with  satisfy all speed and
                                    a certain,       a future location   schedule constraints
                                    multi-block      prediction          with the minimum fuel
                                    preview distance                     expenditure
  --------------------------------- ---------------- ------------------- -----------------------

Askey's proposed decision aids were motivated by a desire to compensate
for human limitations in signal detection and information processing.
Kuehn (1992) examined the efficacy of the Advanced Train Control System
(ATCS) displays with respect to safety and efficiency of operation in
light of these same limitations. He concluded that the ATCS display,
which incorporated a gradient, authority, and speed restriction preview
for five miles ahead of the train, resulted in increased safety (as
measured by the number of speed violations and red signal overruns).
Participants in the ATCS group produced significant reduction in fuel
consumption over the conventional paper warrant group.

Information about the status of the track some distance ahead of the
train is expected to aid locomotive engineers by partially compensating
for the decreased signal processing time imposed by higher train speeds
(above 79 mph). Such preview information may include the signal speed,
the civil speed, track occupancy, and braking characteristics. Providing
the engineer with this information far enough in advance may allow the
engineer to make better (i.e., safer and more efficient) decisions in
the time available.

Both Kuehn (1992) and Askey (1995) demonstrated that displays
incorporating preview information increased safety and efficiency of
train operation. However, neither study focused on the amount of preview
as a variable. The ATCS guideline for preview information was based upon
discussions with engineers. The current study seeks to answer the
question "how does preview distance affect locomotive engineer train
handling performance."

## Research Goals

1.  This research was performed to examine whether preview information
    is useful, and if so, how far down the track should the engineer be
    able to "see." These questions were investigated by measuring
    performance in a human-in-the-loop locomotive simulator.

2.  This study represents the first time locomotive engineers were used
    as participants in the locomotive simulator. Previous experiments
    were conducted using students. A second goal compared the
    performance of locomotive to students.

3.  A third goal was to solicit locomotive engineers' feedback on the
    realism of the part-task simulator after making extensive upgrades.
    The simulator upgrades included adding a cabin environment; track,
    engine and alarm sounds; and more realistic control inputs.

# LOCOMOTIVE CAB DISPLAYS IN HIGH-SPEED OPERATIONS

This section reviews the development of train control systems and
locomotive cab displays in countries with high-speed operations. Based
on this information, along with interviews with locomotive engineers,
locomotive manufacturers, and railroads, a preview decision aid was
developed and tested.

In North America, the railroads developed specifications for modern
train control systems suitable for high-speed operations. The
Association of American Railroads (AAR) and the Railway Association of
Canada (RAC) cooperatively developed specifications for the development
of positive train control systems. Individually, railroads developed
their own requirements for train operation, driven internal needs. These
railroads included Amtrak, Burlington Northern Railroad (BN), Swedish
State Railways, the Japan Rail (JR) companies, Société Nationale des
Chemins de Fer Français (SNCF, the French National Railways), and
Deutsche Bahn AG (DB, German Railways). The manufacturers most directly
involved in the development of the high-speed train control technology
included: AdTranz (acquired by Bombardier); Bombardier; Alstom; General
Electric (GE); and General Motors (GM).

## Sweden

AdTranz manufactured Sweden's high-speed trains, the X2000, the first of
which was put into operation in 1990. Sweden's rail network is
characterized by numerous curves. The curves limit operating speeds due
to tremendous lateral forces that degrade passenger comfort. Sweden's
sparse population made it uneconomical to construct dedicated high-speed
guideways. Consequently, Statens Jarnvagar (SJ, also called Swedish
State Railways) put its effort into redesigning the passenger car
characteristics to increase speeds by up to 35 percent in curves (to 125
mph) and over 50 percent on straight track with no decrement in ride
quality. The X2000 achieves these goals with two improvements over
traditional railroad cars: A mechanism that tilts the cars inwards in
curves (thereby decreasing centrifugal forces on passengers in the cars)
and the improved running characteristics of the "soft" bogies (which
allow the front and rear axles of each bogie to pivot, thereby
decreasing rolling resistance around curves. The resulting smooth ride
received good reviews (Wilner, 1994).

SJ implemented an incremental transponder-based automatic train control
(ATC) system in operation over its entire network. This system displays
the current and next block signals in the cab as shown in Figure 1. If
the train's speed exceeds 6 mph (10 km/hr) above the permitted speed,
the on-board ATC computer will stop the train. The computer will also
stop the train if the operator fails to reset the alerter at least once
each minute, if the gates at a grade crossing are not lowered in time,
or if the automated induction loop system detects a motor vehicle stuck
in a grade crossing (FRA, 1991a). As all trains operated in Sweden are
required to be compatible with SJ's ATC system, the X2000 is
differentiated from other locomotives with respect to cab displays only
by its fault indication panel, which is designed to aid the engineer in
understanding errors and avoiding unnecessary stops for minor faults.

![](media/image6.wmf){width="4.895833333333333in"
height="1.9909722222222221in"}

[]{#__RefHeading___Toc511535070 .anchor}Figure 1. X2000 Instrument Panel

The X2000 cab displays include a combination of digital and analog
formats. The brake pressure and current speed (the two largest displays
on the instrument panel) are displayed on circular analog dials. The
tractive effort and line voltage, displayed to the right of the
speedometer and brake pressure gauge, are displayed on vertical linear
gauges. For the ATC system to make its calculations properly, the
engineer must enter the train's length, maximum speed, braking capacity
and brake delay via the thumbwheels located above and to the right of
the line voltage gauge. The system indication panel to the left of the
train control panel, shown in Figure 2, consists of twenty backlit,
color-coded lamps, some of which must be interpreted in combination with
information shown in the fault indication panel above the windscreen.
The combination of display paradigms gives the impression of a system
pieced together over time, and recent photographs of the X2000 cab look
much like SJ cabs from the early 1980s.

![](media/image7.wmf){width="2.0340277777777778in"
height="2.811111111111111in"}

[]{#__RefHeading___Toc511535071 .anchor}Figure 2. X2000 Fault Indication
Panel

The item that stands out in comparison to other countries is the digital
display of both the current and next block signal, in the upper
left-hand portion of the display panel. Providing the next block's
signal allows the engineer more time to react to an upcoming signal
change. However, the operator is still required to know the distance and
time to the beginning of the upcoming block. The ATC system relies on
engineer input of train characteristics, like the German system.

## Japan

In Japan, high-speed trains (the Shinkansen) operate throughout the
country on dedicated rights-of-way. There are five types of Shinkansen
power cars in use and three different types of cab displays as shown in
Table 2. The MON4 and MON10 displays are software-generated displays
that give information regarding train location and speed, as well as a
graphical representation of consist and brake status (see Figure 3 and
Figure 4). The current speed limit is indicated by a lighted dot at the
perimeter of the speedometer.[^1] Currently, the operator is given no
information regarding braking distance, distance to the next block,
grade, or other trains' locations.

  --------------------------------- ------------------------- -------------------------
  []{#__RefHeading___Toc513625142                             
  .anchor}Table 2. Shinkansen Power                           
  Car Characteristics                                         

  **Power Car**                     **Production Date**       **Cab Display**

  200                               1981                      MON1

  400                               1990                      MON4

  E1                                1993                      MON4

  E2                                1994                      MON10

  E3                                1994                      MON10
  --------------------------------- ------------------------- -------------------------

There has been a strong push for standardization of cab displays to
improve the design and reduce operator confusion.[^2] Shinkansen
guideways lack wayside signals. Instead, the current block signal is
displayed on the dashboard. In 1995, JR East looked at how to best
display the next block's signal as well. JR East conducted extensive
testing using surveys, simulations, and overlays of information in cabs
in actual operation. JR East felt that giving the engineer more than two
blocks of information was too much, as the engineer would not be able to
use this information (Horiuchi, 1996). Consequently, they focused their
efforts on how best to display the current and next block information.

![](media/image8.wmf){width="5.072222222222222in"
height="3.3027777777777776in"}

[]{#__RefHeading___Toc511535072 .anchor}Figure 3. Shinkansen MON4
Display

![](media/image9.wmf){width="3.7756944444444445in"
height="3.252083333333333in"}

[]{#__RefHeading___Toc511535073 .anchor}Figure 4. Shinkansen MON10
Display

Their preferred design does not show any block signals at all. Instead,
the display contains a circular speedometer with a triangle around the
perimeter that indicates the maximum speed for a given movement
authority. The maximum speed will allow the operator to stop or
decelerate so that the train remains within the limits of its authority
for the next block. If the actual speed of the train is within a certain
buffer range of this indicator, the signal turns yellow. If the actual
speed exceeds the maximum safe speed, the signal becomes red and a
penalty brake application is made. JR East also proposed a distance
gauge that would show the distance between the operating train and the
next train down the track.

## France

In France, the Train à Grande Vitesse (TGV) high-speed trains operate
partially on dedicated rights-of-way and partially on mixed-use
guideways. The manufacturer of the TGV locomotives, Alstom, makes
TGV-type locomotives for use in France and surrounding countries. Due to
the differing operating environments, there are a several different cab
environments on the TGV locomotives. The original TGV locomotives have a
left-hand side operator's position, while newer TGV locomotives have a
central operator's position originally designed to accommodate travel on
foreign tracks where the traffic and signals may be either on the
right-hand (e.g., Germany) or the left-hand (e.g., France and Belgium)
side as shown in Figure 5. The SNCF locomotives use a wheel to control
power output from the motors, while the locomotives for all other
operators use a more conventional traction lever. The newer cabs with
the central operator's position have a much wider instrument panel area
to accommodate the variety of signaling systems in use by the European
railroads.

![](media/image10.wmf){width="4.01875in" height="2.6180555555555554in"}

[]{#__RefHeading___Toc511535074 .anchor}Figure 5. Interior of a TGV-PBKA
Cab

Beginning with the TGV-A in 1988, TGV locomotives were equipped with an
on-board data processing system for conducting train start-up tests,
displaying equipment status, troubleshooting, or assisting with repairs.
The data processing system interface consists of a recessed monitor and
keyboard located to the right of and behind the traction control lever
or wheel. Cab signals are displayed instead of wayside signals on the
dedicated high-speed guideways. The cab signaling provides ten aspects.
The engineer's control task is made somewhat simpler by the fact that
each block is of a uniform length (1^1^/~3~ miles or 2.1 km).

SNCF experimented with a "moving-block" train control system, named
ASTREE, in which the train's speed and location were calculated on-board
and relayed to a central control area where the data is combined with
those of other trains to calculate maximum safe (current) speeds. This
project was halted and the data gathered were used, in part, to develop
the European Train Control System (Jane's World Railways, 1996). The
ASTREE experiment focused more on the central control of the trains,
rather than on the cab display of information to the operator. When it
was developed, it represented one of the more complete implementations
of advanced train control and data link communications. It included such
items as a target speed, an updated schedule, and suggestions for energy
savings (see Figure 6).

![](media/image11.wmf){width="6.495833333333334in"
height="2.0319444444444446in"}

[]{#__RefHeading___Toc511535075 .anchor}Figure 6. ASTREE Cab Display (de
Curzon, 1994)

## Germany

The German high-speed train system, the Inter-City Express (ICE), boasts
the highest level of computer-aided support of any rail network,
allowing manual control, partial computer-assisted speed control, and
fully computer-assisted speed control (FRA, 1991b). During manual
control, the train control system operates in the background. If the
train reaches the nominal speed curve, a warning is given to the
engineer. If the train reaches the monitored speed curve (i.e., that
speed above which the train could not decelerate or stop in time), the
emergency brakes are applied. Before each trip, the engineer must key in
the train identification number, train length, and the status of the
braking systems. During the trip, the engineer must input any changes in
the braking capability of the train to allow the ATC system to make the
necessary calculations accurately.

The cab displays consist of two analog circular gauges for speed and
power in the middle of the dashboard with an angled software-generated
display on either side (see Figure 7). One monitor provides braking
information, while the other displays general diagnostic information.

![](media/image12.wmf){width="4.129861111111111in"
height="3.0027777777777778in"}

[]{#__RefHeading___Toc511535076 .anchor}Figure 7. Interior of an ICE Cab

In 1991, DB instituted a new signaling scheme wherein the trackside
signal displayed the aspect, the effective speed limit (in multiples of
10 km/hr), and the direction of divergence if approaching an
interlocking. The signal indicated the status two blocks ahead of the
train (Jane's, 1996). Thus, the engineer was given greater time in which
to react without transmitting any more information.

In 1995, DB began testing a high-capacity train control scheme based on
fixed-block track. Computer Integrated Railroading (CIR) utilized
shorter block lengths than used previously. Based on current train
positions and speeds, a computer calculated minimum acceptable headways,
which were then relayed to the cab of each respective train. No wayside
signals were used.

## North American Railroads

The AAR and RAC developed a comprehensive set of guidelines outlining
their vision of positive train control called ATCS. ATCS used digital
data communications and computers to manage and control the elements of
the railroad. These elements included locomotives, track forces, field
devices, the dispatch office, and railroad management systems (Moody,
1993). The goal of this system was to improve safety, efficiency, and
customer service. These specifications were revised several times and
several railroads implemented test beds of ATCS-style systems in various
forms (Moody, 1990; Progressive Railroading, 1991).

One of the earliest examples was the Advanced Railroad Electronic System
(ARES) developed by Burlington Northern Railroad (BN) in conjunction
with Rockwell International and tested on the Minnesota Iron Range from
1987 to 1993. ARES was an ambitious train control project, encompassing
automated traffic planning and assessment, computerized dispatching and
record keeping, cab command and control, improved data links, automatic
location and speed monitoring, and locomotive health and status
monitoring (Ditmeyer and Smith, 1993; Moody, 1990). The ARES cab
display, called the Train Situation Indicator, displayed route profile
and alignment, grade crossing locations, sidings and other physical
structures, and train movement authorities.

The FRA, Amtrak, the State of Michigan, and GE Harris-Harmon Electronics
developed a system called Incremental Train Control System (ITCS) on a
passenger corridor between Detroit and Chicago. The AAR, FRA, and the
State of Illinois joined together to develop the North American Joint
Positive Train Control System (NAJPTCP) for the Chicago -- St. Louis,
Illinois corridor. Lockheed Martin served as the contractor for this PTC
system.

The ATCS guidelines provide for computer-assisted support of train
control. While the locomotive engineer is nominally in control of the
train, the computer-based train control system can override any engineer
actions that would result in an unsafe situation. The ATCS
specifications outline two types of cab displays. One display emphasizes
train control parameters and the other displays track and movement
authority information. These displays are shown in Figure 8 and Figure
9, respectively.

![](media/image13.wmf){width="3.4298611111111112in"
height="2.7506944444444446in"}

[]{#__RefHeading___Toc511535077 .anchor}Figure 8. LSI (Train Control)
Display

These guidelines designate what types of information are required and
what information is optional. The guidelines discuss how these pieces of
information should appear on the screen (see Figure 8 and Figure 9). The
train control display indicates where each piece of information should
appear on the screen and delineates an area for "optional" information,
such as train control notices. The track authority display can be either
graphical or text based. The suggested graphical track display
incorporates many of the same concepts encompassed by Askey's (1995)
preview, predictor, and advisor displays.

![](media/image14.wmf){width="6.499305555555556in" height="5.01875in"}

[]{#__RefHeading___Toc511535078 .anchor}Figure 9. AAR ATCS
(Track/Authority) Display

Tests performed at IITRI demonstrated increased safety and efficiency of
train operation when the ATCS display was compared to the traditional
paper warrants (Kuehn, 1992). These results show the promise of such
decision aids.

## Amtrak

Since the national 79 mph speed limit was instituted in 1947 (Wilner,
1994), the migration to higher speeds in the United States has been
slow, consisting of incremental increases in maximum safe operating
speeds. To travel above 79 mph, a train must be equipped with cab
signaling or automatic train protection (ATP). Train control systems
with ATP initiate a penalty brake application if the speed limit or
movement authority is violated.

The Genesis Series II cabs, put into revenue service in 1995, marked the
first use of software-generated displays used by Amtrak. The Genesis cab
used a desktop style control stand and included three computer display
screens (two for the engineer, and one for the conductor). The auxiliary
function display is complex, with several menu-driven levels that can be
selected using function keys. Figure 10 shows the primary display the
engineers used in routine train control. The general response to both
the cab and the display was positive. However, some engineers felt that
the Series II displays were too "busy," and that a circular speedometer
(like the traditional circular analog gauges) was better than the linear
version.

![](media/image15.wmf){width="4.050694444444445in"
height="2.777083333333333in"}

[]{#__RefHeading___Toc511535079 .anchor}Figure 10. GE/Amtrak Genesis II
Gauge Display

## Summary

A wide variety of cab display paradigms were used in the countries
operating high-speed trains. The differences that exist include many
important aspects of train control and cab display design. The
differences in information displayed include, but are not limited to:
the kind of information provided (e.g., fault indication lights), the
level or amount of information provided (e.g., one block or two blocks
of signals), and the presentation of this information. For instance,
Japanese engineers favor linear speedometers, while American engineers
favor circular speedometers. Sweden presents the operator with the
current and next block signals, while Japan and the United States only
display the current block signal. Japanese and French railroads do not
have wayside signals on high-speed corridors, while the United States
and Swedish railroads do have wayside signals.

The variety of cab display conventions suggests a number of different
avenues for research. Each country has its own convention regarding how
train control information (speed, traction and braking) is displayed.
This raises the question: to what extent does the way train control
information is displayed (e.g., horizontal versus vertical, linear
versus circular, etc.) affect how the engineer operates the train?
Within a railroad, there is also variation within individual operators'
territory, with respect to signaling paradigms and display regimes. This
variation has the potential to cause confusion among engineers who may
have to operate a different locomotive (with different displays) on any
given day. A uniform signaling system and as uniform a cab environment
as possible would increase safety by reducing confusion and minimizing
operator errors.

There also seems to be consensus among the railroads in the various
countries operating trains at high speeds that the engineer needs
information over and above the current block signal. However, nowhere is
an engineer given any information about distance further ahead than the
next block. The results of Kuehn (1992) suggests that preview
information may be helpful not only for safety, but for efficiency as
well. However, it remains unclear what level of preview, or how far down
the track that information is provided, is most useful. The current
research seeks to build on this knowledge regarding "preview
information" by specifically examining the length of preview on
locomotive engineer performance.

# SIMULATOR EXPERIMENT

## Overview

This experiment examined the differences in safety and efficiency of
train operation that might arise by using displays with and without
preview information. Information that is helpful to the engineer may
include upcoming speed restrictions, location and velocity of nearby
traffic, and upcoming distance cues (such as mileposts). This
information was included in an experimental display. This display was
compared to the Genesis II display used in Amtrak locomotives. The
Genesis II display shows in-cab signals, but does not provide preview
information.[^3]

To investigate these questions, an experiment was run on a
human-in-the-loop locomotive simulator, using locomotive engineers and
students. A second goal of the research was to compare the performance
of engineers and non-engineers. Previous studies using the locomotive
simulator were conducted using only students as participants. Can the
results of these studies be applied to locomotive engineers? Evaluating
performance for both groups allows better understanding of the benefits
and limitations of using students in a job that requires a high level of
training to become proficient.

## Locomotive Simulator

The simulator consists of three networked Silicon Graphics computers and
one Windows-based computer. When operating the train, the participant
sat in a simulated locomotive cab, which included a 17-inch display
monitor (showing the computer-generated instrument panel), one control
box on either side of the monitor, and a window through which the
participant viewed a computer-generated image of the out-the-window
(OTW) view on a 6-by 4-foot screen. The participant communicated with
the dispatcher by two-way radio. Track and engine noises tied to the
simulation were broadcast via speakers in the cab. Figure 11 shows a
photograph of the cab environment. The two control boxes on either side
of the monitor governed the emergency brake, doors, cruise control,
alerter, overspeed warnings, bell, horn, and circuit breakers. A
separate workstation functioned as the dispatcher's workstation,
allowing the dispatcher to control all the switches and authorities. In
these experiments, the experimenter performed the duties of the
dispatcher. See (Lanzilotta, 1996) and (Askey, 1995) for further
descriptions of the locomotive simulator.

![](media/image16.jpeg){width="5.25in" height="3.5in"}

> []{#__RefHeading___Toc511535080 .anchor}Figure 11. Simulated
> Locomotive Cab

## Experimental Design

### Independent Variables

The independent variables manipulated were preview distance and
participant type. Two displays were used to show the different preview
distances. The baseline display was a mock-up of the Genesis II display,
shown in Figure 12. This display showed only the current block signal
(no preview information) in the form of a location-coded signal and
digital readouts of the civil and signal speed limits. The other display
conditions were all variations of one experimental display that showed
the same brake, traction and warning information as the Genesis II
display, but also contains speed-by-distance and traffic preview
information as shown in Figure 13.

The large window in the middle of the preview display showed the
upcoming speed restrictions. The horizontal axis scaled with distance,
while the vertical axis scaled with speed. The vertical white line in
this portion of the display indicated the current train position, while
the short horizontal white line emanating from the vertical white line
indicated the train's length as well as its speed. The horizontal and
vertical red lines indicated the maximum allowable speed at that
location.

If the white horizontal bar indicating the train's current location was
above the red line, the train was violating the effective speed limit.
Mileposts, switches, and stations were indicated just below the speed
preview window, above the track preview display (described on the next
page).

The preview displays also displayed predictive full-service and
emergency braking curves. The yellow curve indicated the speed profile
for a full-service brake application. The red curve indicated the speed
profile for an emergency brake application. The green curve indicated
the speed profile for the coming 25 seconds given current grades and
control input. As the amount of power or braking changed, the predicted
trajectory changed accordingly. ![](media/image17.png){width="6.15in"
height="4.950694444444444in"}

![](media/image18.png){width="6.401388888888889in"
height="5.184722222222222in"}

[]{#__RefHeading___Toc511535082 .anchor}Figure 13. Preview Display

The smaller window below the speed preview window shows the upcoming
track structure and authorities. Green indicated authority to move in
that portion of track, while red indicated a lack of authority. The
horizontal (distance) axis is on the same scale as the speed preview
sub-display, and the same milepost, switch, and station indications
apply.

Preview distance was controlled by varying the resolution of the
horizontal (distance) axis on the speed and traffic preview sub-displays
to control how far down the track the operator can "see." One hypothesis
was that the stopping distance is the most influential factor when
considering how far down the track the engineer needs to be able to see.
Thus, one preview condition (variable preview) was a function of
stopping distance at full-service braking and "reaction plus decision"
distance (approximately reaction time plus "decision time" multiplied by
current speed, ignoring acceleration during that same time period). As
the train's speed increased, the preview distance provided to the
engineer increased accordingly. The variable preview display always
provided the status of the track at least some distance ahead of the end
of the full-service braking predictive curve (i.e., the resolution of
the horizontal axis decreased, as the display provided information about
the status of the track further ahead of the train's current location).
This "variable preview" display had 1,640 feet as the minimum preview
offered at low speeds. The other (fixed) preview distances (see Table 3)
were zero, 1.4 miles (approximately two blocks, mimicking the level of
information now available in Sweden), and 3.4 miles (which is higher
than the longest variable preview distance expected at the top speed of
150 mph). Each preview display shows the track about 0.3 miles (1,640
feet) behind the train as well.

[]{#__RefHeading___Toc513625143 .anchor}Table 3. Independent Variables

  ----------------- ----------------- ---------- -------------- -------------- --
  **Participant**   **Preview                                                  
                    Condition**                                                

  **Engineer**      Current block     1.4 miles  3.4 miles\     Variable       
                    only (no preview) (2.24 km)  (5.6 km)                      

  **Student**       Current block     1.4 miles  3.4 miles\     Variable       
                    only (no preview) (2.24 km)  (5.6 km)                      
  ----------------- ----------------- ---------- -------------- -------------- --

### Dependent Variables

#### **Speed Control** {#speed-control .unnumbered}

Speed control was defined here as the ability to maintain or stay below
the permitted speed, once that speed has been reached. A violation of
this requirement could take place during a clear signal, when the civil
limit must be obeyed, or it could take place during a restricted signal,
once the speed required by that limit had been achieved.

Speed control was monitored by collecting data on the train speed
relative to the allowed speed. Locomotive engineers were expected to
keep their trains within a certain range of acceptable values. The
operator was allowed to drive up to 4 mph above the speed limit without
penalty. If the train operated more than 4 mph over the limit longer
than 5 seconds, a penalty brake application (full-service brake
application) was initiated by the train's ATP system. Control of the
train was not returned to the participant until the train's speed was
brought below the speed limit. The simulator automatically recorded the
duration of any overspeed, as well as the number of penalty brake
applications.

#### **Signal Adherence** {#signal-adherence .unnumbered}

A task similar to speed control was signal adherence. Violating a
movement authority (i.e., running past a red "stop" signal) or a missed
signal (i.e., passing a signal at a speed higher than indicated by the
signal) is also speed violation (i.e., the train speed is greater than
the speed limit). Although the outputs (engineer actions) of these two
control tasks were similar, the inputs and decision processes were
different. When controlling the speed under a constant speed limit, the
engineer must decide (based on the operating conditions) whether to
apply the throttle or the brake. When adhering to an (upcoming) signal
change, the engineer must decide at what point to apply the brakes. In
the former (i.e., speed control) case, the engineer risks overshooting
or undershooting the target speed. At most, the initial overshoot will
be just greater than zero, as the train must first cross the speed limit
before surpassing it. In the latter (i.e., signal adherence) case, the
engineer is at risk of severely overshooting the upcoming signal if the
brakes are not applied in time. The initial overspeed could be
significant relative to the new speed limit.

Signal adherence was measured by the number of signal violations (i.e.,
entering a block with a speed greater than that block's limit) and the
magnitude of each violation.

#### **Brake Reaction Time Latency** {#brake-reaction-time-latency .unnumbered}

Brake reaction time latency to failure scenarios (i.e., a car stuck in a
grade crossing or a dropped signal) was monitored by recording reaction
times to take action in response to a "failure" event (i.e., the
distance between the train and the event, such as a signal or a car
stuck in a crossing). The time of the event was automatically recorded
in the data log. If the response fell within the domain of predictable
actions, it too was recorded. The reaction time was measured from the
time between the event and the initiation of the participant's response.

#### **Schedule Deviation** {#schedule-deviation .unnumbered}

Schedule deviation was measured by the difference between the expected
arrival time at each station and the actual arrival time at each
station.

#### **Station-Stopping Accuracy** {#station-stopping-accuracy .unnumbered}

Station-stopping accuracy was measured by comparing the participant's
actual stopping location at each station relative to a pre-defined mark
(the end of each station platform). In passenger operations,
station-stopping accuracy is an important part of the engineer's job. An
inaccurate stop may require the conductors to perform extra work and may
force the passengers to lug their bags to different exits.

## Task

Each participant operated the locomotive simulator on a section of track
modeled after a trip from South Station in Boston, Massachusetts to
Attleboro, Massachusetts. The trip included two intermediate stations
(Sharon and Foxboro). The time between each station averaged 12 minutes,
bringing the total travel time to approximately 37 minutes. The
participant's task was to operate the train, given the schedule
constraints and operating conditions. The participant encountered a
variety of disturbances, as described in Table 4. The trip between
Boston and Attleboro was divided into three legs (from Boston to Sharon,
from Sharon to Foxboro, and from Foxboro to Attleboro). The participant
encountered disturbances in two of these three legs.

[]{#__RefHeading___Toc513625144 .anchor}Table 4. Operating Disturbances

  ----------------- -----------------------------------------------------------
  **Disturbance**   **Description**

  **1**             Take a siding or crossover to a parallel track due to an
                    unexpected train moving in the opposite direction.

  **2**             Respond to an unexpected change to a restricted signal
                    (i.e., a "stop" signal).

  **3**             Respond to an unexpected change to a restricted signal
                    (i.e., a stop signal due to a relay failure).

  **4**             Respond to a temporary speed restriction.
  ----------------- -----------------------------------------------------------

With four different values for the independent variable (no preview,
variable preview, 1.4 miles, and 3.4 miles) and two disturbances per
trip, each participant ran one trip with each display and saw eight
disturbances: two on each display. With four different types of
disturbances, each participant encountered each type of disturbance
twice. Thus, each participant experienced four Boston-Attleboro trips
(two round-trips), making each trip with a different cab display. After
completing both trips, each participant completed a questionnaire and
answered questions to collect opinions about the effectiveness of each
display.

## Participants

Three Amtrak locomotive engineers and six MIT students participated in
this experiment. The locomotive engineers were three males with between
10 and 29 years of service as engineers. All engineers worked as
passenger train engineers, with some freight experience mixed in. The
youngest engineer was 45 years old. The six students consisted of four
current MIT students and two recent graduates. The students were males
between 19 and 23 years old. None of the students had any experience
operating trains.

The presentation order of the displays and the disturbances was
counterbalanced across participants. The experiment was originally
designed to use an equal number of locomotive engineers and students.
However, only three of the proposed six Amtrak engineers were able to
participate in the time allotted to running experiments, due to
scheduling difficulties. Therefore, the counterbalanced design was
incomplete for the locomotive engineers.

## Training

Due to the two groups' varying experience with train control (greater
for the engineers) and working with computers (greater for the
students), the training regimens were different for the two groups.
Training procedures for students were developed during the previous two
experiments using the locomotive simulator (Askey, 1995; Lanzilotta,
1996).

### Student Training

Each participant was given a written tutorial of train control and
simulator operation issues to read before arriving for the first
session. After reviewing the material, the participant answered 25
multiple-choice questions. After reviewing incorrect answers with the
participant and answering any questions, the experimenter led the
participant through one trip between South Station and Attleboro
(lasting approximately 1 hour). The participant saw each of the displays
to be used during the experiment. The experimenter demonstrated all
train control modes, how to communicate with the dispatcher, and the
meaning of each piece of information displayed on the monitor. After
answering all questions, the participant practiced operating the train
on five trips (lasting approximately 4 hours) between Boston and
Attleboro. During the first leg, there were no disturbances. The next
four legs had at least one of the disturbances.

The student's performance with respect to schedule adherence,
station-stopping, signal adherence and speed control was measured. If a
student consistently performed at an acceptable level by the end of the
second full round-trip, the training was terminated at the end of that
trip and the experimental trials began. Four of the six student
participants completed the training by

the end of the second full round trip. If the student performed at an
unacceptable level by the final training trip, the student's
participation ended. All students completed the training successfully.

### Engineers

Although the locomotive engineers had extensive experience operating
locomotives, they still needed a significant amount of time to learn how
to operate the locomotive simulator and become familiar with the
operator interface. The locomotive engineers were given a short version
of the tutorial to read. The locomotive engineers were given an
opportunity to review the material with the experimenter and ask
questions.

Each engineer's participation lasted one full day. The engineers'
training sessions consisted of an instructional portion and a test
portion. During the instructional portion, the participant saw each of
the displays and each of the disturbances while being talked through the
operation of the train by the instructor. The instructional portion
lasted 1 hour. The engineer practiced operating the train on three trips
with disturbances (lasting approximately 2 1/2 hours) to become familiar
with train operation.

# RESULTS AND DISCUSSION

## Speed Control

Table 5 shows the frequency of speed violations by display condition.
The student group averaged 1.66 instances of speeding (ten events),
while the engineer group averaged 1.33 instances of speeding (four
events). The largest number of speed violations occurred in the
no-preview display condition. The number of speed violations in the
no-preview condition was greater than with all preview displays,
combined. This result suggests that speed control was more difficult
using the no-preview display.

The minimum overspeed using three of the four displays was just over
four mph. The ATP system in the locomotive simulator allowed a "buffer"
zone of four mph over the effective speed limit before any warning or
punishment was given.

  --------------------------------- ----------- -------- -------- --------------
  []{#__RefHeading___Toc513625145                                 
  .anchor}Table 5. Frequency of                                   
  Speed Violations by Display                                     
  Condition                                                       

                                    Preview                       
                                    Condition                     

                                    None        1.4 Mile 3.4 Mile Variable

  Speed Violation Frequency         8           2        3        1
  --------------------------------- ----------- -------- -------- --------------

In five of the six speed violations in the preview conditions, students
were approaching the point where the civil speed limit increased and
were accelerating before entering the block with the higher speed limit.
These five violations lasted from 0.1 to 5.1 seconds, and the maximum
speed violation reached as high as 12.7 mph above the speed limit. One
possible conclusion to draw from this behavior is that they were
anticipating the speed limit increase shown on the preview display.
Participants may not have built up enough knowledge of the territory to
know exactly how far away the point was from where the civil limit
increases, whereas (in real train operation) locomotive engineers know
that information readily.

The other eight instances of speeding occurred with the no-preview
display. Routine speed control may be harder with the no-preview display
than with the preview displays. Despite their practice runs, all of the
engineers expressed difficultly in controlling the train without any
previous knowledge of the train's braking and acceleration
characteristics. This difficulty was exacerbated when using the
no-preview display.

## Signal Adherence

Signal adherence here refers to the operator's ability to control the
train's speed in response to unexpected signal changes. Table 6 shows
the speed adherence performance of the two groups by display condition.
Students and locomotive engineers performed similarly, with the most
signal overruns in each group occurring in the no-preview display
condition. Performance with regard to red ("stop") signals, however, was
nearly identical between the two groups and across the different display
conditions.

  --------------------------------- ------------------------ ----------- ---------- ---------- ----------
  []{#__RefHeading___Toc513625146                                                              
  .anchor}Table 6. Signal Adherence                                                            
  by Preview Condition                                                                         

                                                             Preview                           
                                                             Condition                         

                                                             None        1.4-mile   3.4-mile   Variable

  Students                          Average Number of Signal 6.3         4.2        2.8        3.5
                                    Violations                                                 

                                    Average Length of Signal 1943        1890       2318       1890
                                    Overrun (ft)[^4]                                           

                                    Average Initial Speed    44.8        57.7       70.1       70.2
                                    Deviation (mph)                                            

  Locomotive Engineers              Average Number of Signal 7.3         5          4.6        1.66
                                    Violations                                                 

                                    Average Length of Signal 1890        1352       2466       2091
                                    Overrun (ft)                                               

                                    Average Initial Speed    32.4        48.5       59.1       68.1
                                    Deviation (mph)                                            
  --------------------------------- ------------------------ ----------- ---------- ---------- ----------

The data indicated similar performance for the two groups with respect
to signal adherence. Students violated an average of 16.8 signals while
engineers violated an average of 18.6 signals. Both groups violated the
most signals in the no-preview display condition.

The average speed of the signal violation was lowest with the no-preview
display and the 1.4 mile fixed preview display. This result was
surprising given the hypothesis that greater preview distance should
give the operator time to respond to a signal change. One explanation is
that the participants braked less aggressively with the longer preview
displays because they could see the distance in which they had to slow
down, whereas with the no-preview display, they did not know when the
next more restrictive signal would come. Locomotive engineers knew what
each signal indicated about the possible signal levels for the next
block and adjusted their speed accordingly. For instance, if the signal
for the current block was 45 mph (approach medium) for the current block
and 30 mph (approach) for the next block, the engineer may not slow the
train down immediately saving some trip time. However, the participants
were not familiar enough with the block and signal locations in the
simulation to exhibit this behavior.

One of the most dangerous situations in operating a train occurs when
passing a red signal. Table 7 shows the average overrun by display
condition. There were 17 red signal violations between both groups. The
results were similar for the two groups. In every case, the signal
turned red within the participant's visual range. In every case, the
participant was unable to stop the

train in time to comply with the signal. Overall, there was little
difference between the preview and no preview displays.

  --------------------------------- ----------- --------- --------- ------------
  []{#__RefHeading___Toc513625147                                   
  .anchor}Table 7. Stop Signal                                      
  Overruns                                                          

                                    Preview                         
                                    Condition                       

                                    None        1.4 Mile  3.4 Mile  Variable

  Mean Red Signal Overrun (ft)      3623        3400      3487      3274
  --------------------------------- ----------- --------- --------- ------------

During the experiment, it became clear that the engineers did not treat
signal limits as absolute. Railroad operating rules provide a margin for
error so that the engineer could operate a few miles above the posted
speed limit without being in violation of a movement authority.
Operating a train at speeds greater than indicated by the signaling
system was not viewed as a safety hazard or as a poor reflection of the
operator's abilities.

## Brake Response Latency

Table 8 shows the time between the first restricted signal passed and
initiation of braking for two signal conditions. In the static signal
condition, the red signal was set from the beginning of the trip. In the
dynamic signal condition, the signal was set when the train was within a
few miles of the signal. Negative numbers indicate that braking was
initiated before passing the signal while positive numbers indicate that
braking was initiated after passing the signal. The more negative the
number, the greater the "cushion" between the act of braking and the
more restrictive speed required by the non-clear signal. Performance was
not a function of preview distance. Response latencies were shortest
with the preview displays than the no-preview condition.

  --------------------------------- ----------- ---------- ----------- ------------------
  []{#__RefHeading___Toc513625148                                      
  .anchor}Table 8. Mean Brake                                          
  Response Latency (s) to                                              
  Restricted Signal                                                    

                                    Preview                            
                                    Condition                          

  Signal Type                       None        1.4-mile   3.4-mile    Variable

  Static                            1.7         -18.3      -5.7        -23.4

  Dynamic                           1.87        1.32       .03         -2.51
  --------------------------------- ----------- ---------- ----------- ------------------

Participants performed best with the variable preview display followed
by the 1.4-mile display and the 3.4-mile display. Although the trend was
the same for both static and dynamic signals, the preview displays
offered fewer benefits in the dynamic signal condition. The response
latency was considerably smaller for the variable display and 1.4-mile
display conditions.

## Schedule Deviation

Schedule adherence is one of the measures by which passengers judge
railroad service. Table 9 shows the schedule deviations by display
condition. Very few schedule delays occurred for trips

that lacked signal changes. Each participant arrived early at the next
station almost every time. The early arrival was related to the time
given to get to the next station. As the time given to get to the next
station increased, the size of the early arrival increased. Although the
participants knew that they would be penalized for arriving at a station
too early, almost every trip without a signal change resulted in an
early arrival. When a participant encountered a signal change, time was
invariably lost, and the schedule could no longer be met, so those
situations were not considered. The experimenter asked each participant
to try to maintain the time differential between stations set by the
schedule (e.g., "Always leave 13 minutes to get from Sharon to Foxboro,
even if you are behind schedule.") However, participants consistently
did not follow this instruction. The participants may have misunderstood
this instruction, forgot the instruction, or tried to make up for lost
time.

The data were inconclusive with respect to the impact of preview
information on schedule adherence.

  --------------------------------- ---------- ------------ ---------- ---------- ----------
  []{#__RefHeading___Toc513625149                                                 
  .anchor}Table 9. Schedule                                                       
  Deviation by Display Number for                                                 
  Trips without a Signal Change                                                   

                                               Schedule                           
                                               Deviation                          
                                               (s)                                

                                               Preview                            
                                               Condition                          

  Track Segment                     Schedule   None         1.4-mile   3.4-mile   Variable
                                    (s)                                           

  S. Station to Sharon              420        28.2         66.6       9.0        31.2

  Sharon to Foxboro                 780                     25.2       -3.0       

  Foxboro to Attleboro              960        46.2                    56.4       67.8

  Loop                              90         18.0         21.0       17.4       19.8

  Attleboro to Foxboro              960                     58.2       69.6       

  Foxboro to Sharon                 780                     -0.6       0.6        

  Sharon to S. Station              480        31.8                               34.8

  Mean Absolute Deviation                      31.1         34.3       26.0       38.4
  --------------------------------- ---------- ------------ ---------- ---------- ----------

## Station-Stopping Accuracy

The locomotive engineer must be able to accurately stop at a particular
point in the station to allow passengers to get out at the correct door.
The inability to achieve such a stop smoothly and on the first attempt
may result in excess fuel consumption, passenger discomfort,
aggravation, or all of above which reflects negatively on an engineer's
performance. The participants were instructed that deviations between
--32.8 ft and +19.7 ft were acceptable, and that overshoots were
penalized more than undershoots (the engineer can always inch the train
forward, but backing up is much more difficult and sometimes
prohibited). The locomotive engineers experienced more trouble stopping
accurately at the stations than the students. They indicated that this
was due to a lack of experience with the train handling characteristics
(i.e., the braking and acceleration of the train) and the territory.
Variation in performance between the displays

was low, as shown in Table 10. There was qualitative data both in favor
of and against the preview displays regarding this task.

  --------------------------------- ----------- ---------- ---------- -----------------
  []{#__RefHeading___Toc513625150                                     
  .anchor}Table 10. Mean                                              
  Station-Stopping Accuracy (ft) by                                   
  Group                                                               

                                    Preview                           
                                    Condition                         

  Group                             None        1.4-mile   3.4-mile   Variable

  Student                           11.5        15.7       10.5       11.8

  Engineer                          21.3        21.3       16.1       13.5
  --------------------------------- ----------- ---------- ---------- -----------------

The data presented in Table 10 indicate that preview information has
little or no effect on stopping accuracy. Some participants reported
trouble stopping accurately with the preview displays. One locomotive
engineer misjudged the braking distance to the end of a station platform
by looking at the display and used the emergency brake. An emergency
brake application in a non safety-critical situation would be considered
poor operating practice. The participant was using the 3.4-mile fixed
preview display, which offered poor resolution for accurate stopping at
low speeds. Several other participants, both students and engineers,
also reported trouble using the fixed-preview displays for accurate
station stopping. These comments support the assertion that the preview
displays were poorly suited for aiding accurate station stops. The
variable preview display was also considered difficult to use. Several
participants expressed their dislike for the constant recalculation of
the scale on the variable-preview display. This observation suggests a
display in which the display scale continually changes may be difficult
to use.

One possible solution is to change the scale of the preview displays at
lower speeds to show a smaller portion of the track in greater detail.
Simply looking out the window may provide the best source of information
to stop or control the train at very low speeds.

## Comparison Between Engineers and Students

The performance between the students and locomotive engineers showed
mixed results. The two groups performed similarly on speed control and
signal adherence and differently on initiating a braking response to a
restricted signal and station-stopping accuracy.

The students performed consistently better than the engineers with
regard to station-stopping accuracy. The engineers said that their lack
of experience with the train's dynamics and the track features adversely
affected their performance. The simulator's train dynamics were modeled
after the TGV, a locomotive with which the engineers were unfamiliar.
The engineers operated locomotives like the General Motors SD40 that had
braking and acceleration characteristics that were considerably
different from the TGV locomotive. Locomotive engineers learn the
characteristics of the territory over which they will operate over a
considerable period. This knowledge is critical to successfully stopping
a train at a station. However, the locomotive engineers had only an hour
or two to become familiar with the train handling characteristics and
the territory. The students received more training time to learn to
operate the train and become familiar with the territory. These
difficulties could be addressed by modeling the dynamics of a

train with which the engineers were familiar and displaying features in
the out-the-window view that exist on the territory over which the
engineers operate.

The engineers and students also differed in their initiation of braking
in response to a restricted signal. Table 11 shows mean braking response
latency for both groups. Negative numbers indicate that braking was
initiated before passing the signal. Positive numbers indicate that
braking was initiated after passing the signal. The more negative the
number, the greater the "cushion" between the act of braking and the
onset of the more restrictive speed. The students began braking earlier
than the engineers in all of the preview display conditions and later in
the no-preview condition.

  --------------------------------- ------------ ---------- ---------- ----------------------
  []{#__RefHeading___Toc513625151                                      
  .anchor}Table 11. Mean Brake                                         
  Response Time (s) by Group                                           

                                    Preview                            
                                    Condition                          

  Group                             None         1.4-mile   3.4-mile   Variable

                                    Expected                           
                                    (Static)                           
                                    Signal                             

  Engineers                         1.4          -15.7      -4.5       -19.1

  Students                          1.8          -20.0      -6.2       -27.7

                                    Unexpected                         
                                    (Dynamic)                          
                                    Signal                             

  Engineers                         1.6          1.5        1.2        -0.3

  Students                          1.9          1.2        -0.7       -3.4
  --------------------------------- ------------ ---------- ---------- ----------------------

These differences may reflect differences in the attention allocation
strategies between the two groups. The engineers obtain information by
looking out the window to determine when to brake. Focusing their
attention out the window is also important to look out for hazards such
as trespassers and motor vehicles in grade crossings. With less
experience operating trains, the students may have had more difficulty
determining when to initiate braking in the no-preview condition. In the
preview conditions, the students may have relied more heavily on the
braking information supplied by the preview displays to determine when
to brake.

The difference in the engineers' reaction times between the no-preview
and preview displays makes sense in light of the engineers' expressed
need to focus attention out the window, thus keeping their attention
away from the tool that would allow them to react sooner. The students
were not trained to focus their attention out the window and were able
to more quickly respond to events in the cab.

# SUMMARY

As trains travel faster, locomotive engineers must process more
information in less time. Providing information far enough in advance to
process and take action may enable the locomotive engineer to more
safely operate the train at high speeds.

In this study, the preview displays improved performance on tasks where
the locomotive engineer's train control actions were made in advance of
the visual information needed to support those actions. Preview
information may prove most valuable to engineers learning to operate in
an unfamiliar territory or in conditions such as poor weather where the
visual information that the engineer normally relies upon is
unavailable. One engineer said that, while he liked the preview display,
the extra information provided would not have been necessary had he
better known the "physical characteristics" of the train and territory.

More specific results include:

-   Routine speed control under a static signal was improved with the
    preview displays, though again, it is unclear whether this
    difference would exist for the locomotive engineers if they were
    more familiar with the territory and train's dynamics.

-   The number of signal overruns decreased with preview information.

-   Braking response time improved with the preview information,
    particularly with the variable preview display.

-   Preview information did not seem to influence station-stopping
    accuracy, though the 1.4-mile (shorter) fixed preview display
    resulted in station stops that were more deviant than with the other
    displays. There was qualitative data supporting each of the types of
    display with respect to station stopping. All of the preview
    displays received high marks for providing good information
    regarding stopping distance from higher speeds, while the variable
    preview display also received praise for increasing the resolution
    at lower speeds, thereby allowing more accurate stops.

-   Among the preview displays, performance with respect to signal
    overruns was poorest with the 3.4-mile fixed preview display.

-   Participants demonstrated an easier time making control decisions in
    the variable preview condition. They exhibited the best braking
    performance using the variable preview display, when exposed to an
    expected (static) or unexpected (dynamic) signal. Participants using
    the 1.4-mile fixed preview display performed better when faced with
    an expected signal than when using the 3.4-mile fixed preview
    display. When faced with an unexpected signal, the opposite result
    occurred. Participants performed better using the 3.4-mile preview
    display than the 1.4-mile preview display.

Qualitative data from this study supports the quantitative data
described above that long preview or preview that scales with speed
(offering greater resolution at lower speeds) is preferable. As one
participant put it:

> *The 3.4-mile preview display made control easiest. The reason I felt
> variable preview was a little less effective is because you (the
> operator) \[sic\] had to scale distances as a part of the
> interpretation. It took some getting used to. The 1.4-mile display was
> my least favorite of the preview displays because you could not see
> the entire predicted braking curves at high speeds*.

When asked what preview distance would make the job easiest, most of the
participants responded "as much as possible" or referred to either the
3.4-mile fixed preview or the variable preview, while one engineer
responded "5 to 10 miles." Another engineer responded, "No preview is
needed if you know the physical characteristics \[of the train and
track\]," though a much higher processing burden is then placed on the
engineer, particularly in critical situations. In general, preview
distance should be at least the minimum stopping distance plus some
buffer distance to account for reaction time.

The Amtrak engineers reacted favorably to the preview displays,
particularly since they "helped learn the territory." It is unclear
whether the engineers would have found the preview displays as useful if
they already knew the territory and the train's dynamics. In low
visibility conditions where locomotive engineers cannot rely on the
normal visual cues, a preview display may prove beneficial.

In designing such information aids, particular attention needs to be
paid to how engineers allocate their attention. The engineers who
operated the locomotive simulator liked the preview displays and
performed well with them. One engineer indicated that the preview
displays aided navigation in unfamiliar territory and were useful to see
the rate of deceleration relative to distance.

However, two of the engineers stressed their need to focus attention out
the window. One engineer complained about the amount of "electronic
harassment" in modern locomotive cabs precluding engineers from focusing
their attention out the window. That engineer said that the engineer's
attention is not necessarily needed to brake in time for a potential
emergency, but rather to be able to blow the horn in time in such a
case, or to accurately control the train when approaching a station
platform. In fact, this participant related that many engineers "cut
out" (turn off) the cab signaling and ATP in low-speed territory to
remove the "distraction" of the warnings and focus their attention on
very fine control of the train's speed. However, the danger is that they
forget to cut it back in when they return to high-speed territory.

With regard to station stopping accuracy, there was evidence that the
preview displays adversely affected performance, due to the lack of
resolution at lower speeds. The best information to support station
stopping is to look out the window. To aid station stopping, the preview
display needs to show enough detail for a locomotive engineer to
properly judge stopping distance.

Research is needed with regard to how this change of resolution should
take place (e.g., continuously or discretely). One way to investigate
this question is to allow the engineer to control the preview distance
and record what is chosen as a function of speed. Future work should
focus on how locomotive engineers allocate their attention, and on how
to effectively incorporate decision aids and training for those aids
into that attention allocation scheme.

The data indicate that the student and engineer groups exhibited similar
behavior in a relatively limited range of conditions. The two groups
exhibited similar behavior towards signal adherence and speed control.
This data suggests that previous experiments using students as
participants may give similar results using locomotive engineers under
two conditions: When locomotive engineers are inexperienced and when the
visual information engineers rely upon to make decisions is
impoverished. Otherwise, the training and operating experience of
experienced locomotive engineers results in behavior that differs from
those of students and others who lack this experience.

# APPENDIX A: TRAIN SCHEDULE {#appendix-a-train-schedule .Appendix-1}

The following page lists the train schedule used by the subjects in the
preview display experiment.

Train Schedule

  ----------------------------------- -----------------------------------
  **[Time]{.underline}**              **[Station]{.underline}**

  00:05:00                            Depart South Station

  00:12:00                            Arrive Sharon

  00:12:30                            Depart Sharon

  00:25:30                            Arrive Foxboro

  00:26:00                            Depart Foxboro

  00:42:00                            Arrive Attleboro (southbound)

  00:42:30                            Depart Attleboro (to loop)

  00:44:00                            Arrive Attleboro (northbound)

  00:44:30                            Depart Attleboro (for South
                                      Station)

  01:00:30                            Arrive Foxboro

  01:01:00                            Depart Foxboro

  01:14:00                            Arrive Sharon

  01:14:30                            Depart Sharon

  01:22:30                            Arrive South Station
  ----------------------------------- -----------------------------------

**Note:** If you are behind schedule, you still must keep the train
doors open for at least 30 seconds at each stop.

# APPENDIX B: EXIT QUESTIONNAIRE {#appendix-b-exit-questionnaire .Appendix-1}

The questionnaire on the following page was given to the experimental
subjects after the test sessions had been completed. The answers
provided on this questionnaire were used to determine the subjective
evaluation of the instrument panels.

**Exit Questionnaire**

1\. Rate the displays in order of preference by placing a mark in the
appropriate box:

  ------------------- --------- --------- ------------ --------- -----------
                      Liked     Liked     Neutral      Didn't    Didn't like
                      very much           (didn't like like very at all
                                          or dislike)  much      

  no preview                                                     

  1.4 miles (fixed)                                              
  preview                                                        

  3.4 miles (fixed)                                              
  preview                                                        

  variable preview                                               
  ------------------- --------- --------- ------------ --------- -----------

2\. Rate the displays according to how difficult/easy it was to control
the train:

  ------------------- ------------- ------------- ------------- ------------- -------------
                      Controlling   Controlling   Controlling   Controlling   Controlling
                      train was     train was     train was not train was     train was
                      very easy     easy          easy or hard  difficult     very
                                                                              difficult

  no preview                                                                  

  1.4 miles (fixed)                                                           
  preview                                                                     

  3.4 miles (fixed)                                                           
  preview                                                                     

  variable preview                                                            
  ------------------- ------------- ------------- ------------- ------------- -------------

3\. Do you feel that the training process provided adequate preparation
for the test task?

\_\_\_\_ adequate training

\_\_\_\_ too little training Explain:

\_\_\_\_ too much training Explain:

4\. How much preview distance (if any) would make the task of train
control easiest?

5\. Any other comments? (Critical comments are appreciated. Feel free to
make comments on the attached pictures.)

# APPENDIX C: FUTURE LOCOMOTIVE SIMULATOR CONSIDERATIONS {#appendix-c-future-locomotive-simulator-considerations .Appendix-1}

One of the goals of this research project was to obtain feedback from
Amtrak locomotive engineers about the realism of the locomotive
simulator. Previous research with the simulator was done using MIT
students as participants. Consequently, previous versions of the
simulator utilized simplistic track networks and unrealistic control
paradigms, such as an alerter whose time interval was independent of
speed, fictitious signal systems, and penalty applications of the
emergency brake.

Throughout the course of this study, two employees from the Volpe
National Transportation Systems Center with prior rail experience and
four Amtrak locomotive engineers operated the locomotive simulator.
During and after each of these sessions, the participants' reactions to
various aspects of the simulation were collected. Some of these comments
were acted upon immediately to improve the simulator's realism. A
plethora of comments, suggestions, and critiques resulting from these
experiments, however, have not yet been acted upon. Many of these
suggestions would significantly enhance future simulations by making
them as realistic as possible.

In general, creating a track structure that more closely represents an
actual environment in which locomotive engineers operate offers several
benefits. First, less training would be required for the engineers. The
engineers would need the same amount of time to learn the operation of
the simulation itself, but would not have to learn braking points and
other reference cues. Second, the closer the simulation is to an actual
rail environment (with respect to both the physical fidelity as well as
to the system response to control inputs) the closer a locomotive
engineer's actions will be to what they would be in the actual rail
environment. One of the engineers indicated that he would have driven
differently had he known the territory better (e.g., he would not have
been focusing on the display, but rather on the out-the-window cues).
Two engineers indicated that they preferred the preview displays over
the no-preview display because it helped them better learn the
unfamiliar territory.

## Changes Needed to Improve the Physical Fidelity {#changes-needed-to-improve-the-physical-fidelity .Appendix-2}

According to one engineer, trains coast at idle, maintaining a constant
speed, whereas the simulator loses a couple of miles per hour per second
at top speeds, due to drag and (track) friction. Maintaining constant
speed at idle does not seem probable, and it is likely that the engineer
simply needs better feedback regarding acceleration and deceleration.
Each of the engineers also said that the acceleration of the simulator
was too slow. The train dynamics in the simulation were based on the TGV
short train set. The acceleration and deceleration characteristics were
tweaked after feedback from the first engineer, but the next two
participants also indicated that these trains were still "sluggish."
Future simulations should use acceleration and braking rates based on
one of the locomotives Amtrak uses, preferably those that will be put
into service at 150 mph in the coming years.

As the engineers use landmarks for remembering braking and speed
reference points, the wayside objects should be more distinctive.
Furthermore, if the sponsors hope to mimic a particular portion of
track, the actual reference point from that portion of track should be
used. This includes not only the wayside objects, but also the block
lengths and signals.

There are several discrepancies related to the wayside signaling system
that need to be resolved:

-   Signal boards with numbers on them indicate a "distant" signal
    (i.e., that the train is approaching an interlocking).

-   A "stop" signal on such a board indicates "stop and proceed" (with
    no further instruction).

-   When there is a number on a signal, the number should be associated
    with a milepost (to 0.1 of a mile), not a block number.

-   The supervisor of the engineers expressed that most Amtrak divisions
    are using "color" signals rather than "location" signals (though he
    said that all engineers should know the location signals).

At a switch, the signal needs to be placed before the switch, not after
it. Also, at any crossover, the signal for the block going in the same
direction on the parallel track (i.e., the block coming into the section
of parallel track into which the engineer's train is crossing) needs to
be set to "stop," indicating that no train on the parallel track can
proceed into the section of track that the participant is about to
enter. Also, the track itself needs to be drawn differently at the
crossover, depending on which way the "frog" (the section of track that
allows the crossover to occur) is attached. At 30 mph or so, the
engineer will visually recognize which way the switch is attached to
determine which direction the train will go in.

Signals should be spaced more like those in the mimicked track; or, at
the very least, they should be spaced farther apart than they are
currently. To change the locations of the signals in the simulation,
which now are based on where road segments begin and end, would be
difficult. The only way to alter signal locations presently is to change
the minimum block length for a signal to be drawn, and this would only
change the number of signals drawn, not the signals' locations. The
signal locations could be read in from a file, similar to the mileposts,
and if there is no file, they could default to the way they are drawn
now. However, then the signal locations would not coincide with road
segment ends, which is how authorities are calculated. A new paradigm
for calculating and enforcing signal territories will likely be quite
time-consuming.

Two engineers said that the "clickety-clack" sounded like "flat" (i.e.,
worn) wheels, though they admitted that they sounded somewhat like
jointed rail. Welded rail apparently does not make that type of noise.
This should be investigated and, if need be, re-recorded.

The equalizing reservoir pressure should read the same as the brake pipe
during release. The brake pipe should "follow" the equalizing reservoir.

One engineer mentioned that it was "strange" that there were no other
trains in the system, but none mentioned the lack of cars at the grade
crossings.

## Changes Needed to Improve Fidelity of Train Control {#changes-needed-to-improve-fidelity-of-train-control .Appendix-2}

During the course of the experiments, we uncovered many ways in which
the train control paradigm of our simulator diverged significantly from
what the engineers were used to:

When encountering a signal that is more restrictive than the previous
signal, the engineer needs to acknowledge that signal by depressing a
button (either a dedicated "signal acknowledge" button, or the alerter),
regardless of the train's speed; if the train's speed is above that of
the new signal, the brake system must be suppressed (i.e., a certain
minimum amount of brake pressure must be applied) to avoid a penalty
application of the full-service brakes. This suppression level may vary
from one train to the next between 14 and 26 psi reduction. This is an
easy change to implement in the software and would be a good first task
for someone trying to learn the simulation.

The engineer normally is required to wait until the rear of the train
has cleared a less restrictive signal before accelerating beyond the old
(more restrictive) signal limit. The train "length" needs to be defined,
and the piece of code that checks the train's speed against the
effective limit should take this into account.

The engineer must wait some period of time after stopping to allow the
brake system to "recharge," or recompress adequate pressure in the brake
pipe to stop the train. This recharging time may be less than a minute
after a full-service application of the brakes, or more than a couple of
minutes if an emergency application is given.

A train is not allowed to approach a bunker (the obstructing "pylon" at
the end of a line) at more than 15 mph (civil limit). If there is no
signal next to or above the bunker, the block approaching the bunker
must be set to "restrict," as the bunker represents an obstruction in
the track. If there is a signal next to or above the bunker, the signal
for the last block approaching the bunker can be set to either
"restrict" or "approach," either of which indicates that the engineer
needs to be prepared to bring the train to a stop before the next
signal. (The engineer who ran past the bunker may not have been helped
by these restrictions, as he entered a 70 mph speed zone at 118 mph.)
These changes should be made in the permanent road databases and in the
dispatcher software, which controls the signals of all trains attached
to it.

The cruise speed should be controllable by the participant. That is, the
participant should be able to key in, or dictate in some other way, a
speed to which the system would then accelerate or decelerate. This is
already implemented in the software, but needs to be activated and
explained in the tutorial. There are several other changes (e.g., the
alerter penalizing with a full-service application of the brakes instead
of a penalty application, the ATP giving a buffer zone above the limit
and penalizing with a full-service application only until the effective
limit is achieved, etc.) that were made to make the simulator mimic, as
close as possible, what the Amtrak engineers are used to. In general,
these changes were implemented with command-line software switches,
leaving the previous options intact as well. Though this system allows
maximum flexibility when running the software, the proper command-line
options need to be learned. Refer to the simulator training manual (at
the Volpe Center) for more details.

## Ways the Engineers' Behavior Differed From Expectations {#ways-the-engineers-behavior-differed-from-expectations .Appendix-2}

The Amtrak engineers' control decisions based on signal levels were
quite different than what had been expected. The engineers expressed
that they might not give any application of the brakes right away (or at
least not a very heavy application) when encountering a more restrictive
signal. They generally know the distance (and thus the time) to the next
signal as well as how restrictive that next signal could possibly be
(i.e., the worst-case scenario) and can set their speed accordingly.
Thus, the engineer might purposefully put the train in an overspeed
situation (to save time, or to keep some brake pressure in reserve) when
encountering a more restrictive signal. Though the speed and control
input are recorded at regular intervals and later can be reviewed, the
locomotive foreman explained that such control behavior did not reflect
poorly in any way on the engineers. In an overspeed situation such as
the one described above (approaching a more restrictive signal at a
speed above the speed indicated by the signal), the engineer has five
seconds to apply the brakes (at any level) before a penalty full-service
application of the brakes is given. If the engineer applies the brakes
before the penalty is applied, the penalty is averted. Some of the
engineers seemed to operate the train in this way (i.e., braking slowly
despite being above the speed limit indicated by the signal), though
others did not (i.e., they observed the speed limit indicated by the
signal).

If a light "drops in your face" (i.e., turns to red when the signal is
already in your range of visibility), it most likely indicates a failure
of the track circuitry, and is thus not necessarily treated as a
complete emergency. If the operator can see the track ahead of him for a
distance equal to or greater than the train's full-service stopping
distance, he might just go to full-service braking, even if that would
mean passing the red signal. However, if there is a siding or any other
portion of the track that he cannot see, the engineer will go to
emergency braking just to be sure.

As mentioned before, several of the engineers expressed that they tend
not to use full-service braking unless the situation requires it, as
they like to keep some pressure in reserve in case of an emergency.
Thus, the engineer would begin decelerating farther in advance than a
full-service application would allow, but at a lower rate (maybe 13 to
16 pounds of reduction[^5]). A couple of the participants had trouble
stopping at the stations accurately at first, due to this aversion to
providing a full-service application of the brakes, but two of the three
engineers performed satisfactorily by the end of the training (i.e.,
after being instructed that the system was designed to require a
full-service application of the brakes). One engineer suggested that
having the full-service braking curve on the preview display would
encourage risk-taking, and suggested having a "14-pound reduction" curve
instead. The engineer who did not perform satisfactorily had to resort
to the emergency brakes for three of the station stops, and actually
crashed through the bunker at South Station at 20 mph.

The locomotive foreman suggested that we gather data on the acceleration
and deceleration forces exerted on the train (as the IITRI simulator
does) and penalize the participants accordingly, as this constitutes a
major part of their training. In particular, the engineers are trained
to avoid using full-service brakes when stopping at a station, to avoid
jolting the passengers. Collecting this data is a straightforward task,
but conveying the forces generated in braking and acceleration may be
difficult if these characteristics are not what the engineers are used
to.

## General Suggestions {#general-suggestions .Appendix-2}

Several participants requested an indication of the "cruise set speed"
on the preview displays when cruise control is active.

Participants' performance might benefit from an audible indication of a
change in the preview display status. The engineers are used to
allocating their attention out the window (usually the side window),
looking for reference points and thus need a cue to check the preview
display more frequently. However, at least one of the engineers also
expressed that he relies heavily on the cab signals and thus checks the
cab displays relatively frequently.

# GLOSSARY {#glossary .Appendix-1}

*Automatic continuous braking systems:* Provide full-service braking
power to each car in the event of a loss of power or a break-in-two.

*Automatic train protection:* Protects the train from over-speed or
signal restriction violations by automatically applying the brakes when
the speed limit is surpassed by a specified amount for a specified
period of time, or when a signal restriction is not acknowledged.

*Cab signaling:* In-cab display of the wayside signals for the current
block.

*Consist:* The combination of rail cars and locomotives that make up the
train.

*Interlocking:* Protect areas around switches, railroad grade crossings,
and crossovers by linking the signal aspect with the interlocking state
and preventing unsafe routings.

*Nominal speed curve:* The speed above which a train cannot decelerate
or stop in time for the next signal, using a full service brake
application.

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[^1]: The earlier displays (series 200) used a linear speedometer
    display. At the engineers' request, the next generation of displays
    (the MON4 in the series 400 and E1) contained circular speedometers.
    When the most recent displays were developed (the MON10 in the
    series E2 and E3), the engineers requested a return to a linear
    speedometer display. Amtrak experienced the opposite situation with
    the Genesis cab. The Genesis locomotive built by GE contained a
    linear speedometer. When the locomotive was purchased from GE for
    operation beginning in the fall of 1996, the engineers requested a
    return to a circular speedometer display like the ones used in the
    older control stand-style locomotive cabs.

[^2]: Except for engineers operating Shinkansen trains, engineers are
    certified by track, not by locomotive. This means that engineers may
    be presented with an unfamiliar cab on any trip.

[^3]: The Genesis II display contained a 60-second speed predictor;
    however, observations of its use indicated that its function was not
    smooth. Engineers interviewed as part of this study indicated that
    they did not trust it or understand it, and did not use it. The
    speed predictor was not included in the experiment.

[^4]: Data excluded eight speed violations (three by engineers, five by
    students) in a crossover section, as these sections were only 50
    feet.

[^5]: Engineers talk about the amount of braking force applied to the
    wheels in terms of "pounds." They are referring to the pounds per
    square inch, or psi, of brake pressure that is exhausted from the
    brake pipe during a brake application. A pressure equal to this
    "reduction" is applied to the brake shoes. The maximum possible
    service application of brakes varies between 24 and 29 pounds,
    depending on the train, with zero pounds (or "no reduction")
    corresponding to no application of the brakes.