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**Identification of Traffic Control Devices for Mobile and Short
Duration Work Operations**

**FINAL REPORT**

**July 2006**

**By**

**Robert E. Paaswell, Ph.D.**

**Director, University Transportation Research Center**

**City College of New York, CUNY**

**Robert F. Baker, M.S.**

**Assistant Director, Research**

**Camille Kamga, Ph.D.**

**Assistant Director, Administration**

**and**

**Nagui M. Rouphail, Ph.D.**

**Director, Institute for Transportation Research and Education**

**North Carolina State University Centennial Campus\
**

In cooperation with

New Jersey Department of Transportation,

And

United States Department of Transportation,

Washington, DC

##### DISCLAIMER STATEMENT

The contents of this report reflect the views of the authors who are
responsible for the facts and the accuracy of the data presented herein.
The contents do not necessarily reflect the official views or policies
of the New Jersey Department of Transportation or the Federal Highway
Administration. This report does not constitute a standard,
specification, or regulation.

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|                        |         |         | TEC    |              |
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|                        |         |         | REPORT |              |
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|                        |         |         | ANDARD |              |
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| 1\. Report No.         | 2.Gov   |         | 3\.    |              |
|                        | ernment |         | Recip  |              |
|                        | Ac      |         | ient's |              |
|                        | cession |         | C      |              |
|                        | No.     |         | atalog |              |
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| FHWA-NJ-2006-006       |         |         |        |              |
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| 4\. Title and Subtitle |         |         | 5\.    |              |
|                        |         |         | Report |              |
|                        |         |         | Date   |              |
+------------------------+---------+---------+--------+--------------+
| Identification of      |         |         | July   |              |
| Traffic Control        |         |         | 2006   |              |
| Devices for Mobile and |         |         |        |              |
| Short Duration Work    |         |         |        |              |
| Operations             |         |         |        |              |
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|                        |         |         | 6\.    |              |
|                        |         |         | Perf   |              |
|                        |         |         | orming |              |
|                        |         |         | Organi |              |
|                        |         |         | zation |              |
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| 7\. Author(s)          |         |         | 8\.    |              |
|                        |         |         | Perf   |              |
|                        |         |         | orming |              |
|                        |         |         | Organi |              |
|                        |         |         | zation |              |
|                        |         |         | Report |              |
|                        |         |         | No.    |              |
+------------------------+---------+---------+--------+--------------+
| Robert E. Paaswell,    |         |         |        |              |
| Ph.D., City College of |         |         |        |              |
| New York               |         |         |        |              |
|                        |         |         |        |              |
| Nagui M. Rouphail,     |         |         |        |              |
| Ph.D., North Carolina  |         |         |        |              |
| State University       |         |         |        |              |
|                        |         |         |        |              |
| Robert F. Baker, M.S.  |         |         |        |              |
| University             |         |         |        |              |
| Transportation         |         |         |        |              |
| Research Center        |         |         |        |              |
|                        |         |         |        |              |
| Camille Kamga, Ph.D.   |         |         |        |              |
| University             |         |         |        |              |
| transportation         |         |         |        |              |
| Research Center        |         |         |        |              |
+------------------------+---------+---------+--------+--------------+
| 9\. Performing         |         |         | 10\.   |              |
| Organization Name and  |         |         | Work   |              |
| Address                |         |         | Unit   |              |
|                        |         |         | No.    |              |
+------------------------+---------+---------+--------+--------------+
| University             |         |         |        |              |
| Transportation         |         |         |        |              |
| Research Center        |         |         |        |              |
|                        |         |         |        |              |
| City College of New    |         |         |        |              |
| York                   |         |         |        |              |
|                        |         |         |        |              |
| New York, NY 10031     |         |         |        |              |
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|                        |         |         | 11\.   |              |
|                        |         |         | Co     |              |
|                        |         |         | ntract |              |
|                        |         |         | or     |              |
|                        |         |         | Grant  |              |
|                        |         |         | No.    |              |
+------------------------+---------+---------+--------+--------------+
|                        |         |         | 49777  |              |
|                        |         |         | -13-05 |              |
+------------------------+---------+---------+--------+--------------+
| 12\. Sponsoring Agency |         |         | 13\.   |              |
| Name and Address       |         |         | Type   |              |
|                        |         |         | of     |              |
|                        |         |         | Report |              |
|                        |         |         | and    |              |
|                        |         |         | Period |              |
|                        |         |         | C      |              |
|                        |         |         | overed |              |
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|                        |         |         | Final  |              |
|                        |         |         | Report |              |
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|                        |         |         | 14\.   |              |
|                        |         |         | Spon   |              |
|                        |         |         | soring |              |
|                        |         |         | Agency |              |
|                        |         |         | Code   |              |
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| 15\. Supplementary     |         |         |        |              |
| Notes                  |         |         |        |              |
+------------------------+---------+---------+--------+--------------+
|                        |         |         |        |              |
+------------------------+---------+---------+--------+--------------+
| 16\. Abstract          |         |         |        |              |
+------------------------+---------+---------+--------+--------------+
| This report documents  |         |         |        |              |
| and summarizes the     |         |         |        |              |
| study "Identification  |         |         |        |              |
| of Traffic Control     |         |         |        |              |
| Devices for Mobile and |         |         |        |              |
| Short Duration Work    |         |         |        |              |
| Operations," for the   |         |         |        |              |
| New Jersey Department  |         |         |        |              |
| of Transportation. The |         |         |        |              |
| study was conducted in |         |         |        |              |
| three tasks: 1.        |         |         |        |              |
| Literature Search, 2.  |         |         |        |              |
| Evaluation Criteria    |         |         |        |              |
| and Analysis, and 3.   |         |         |        |              |
| Identify Guidelines to |         |         |        |              |
| Eliminate Driver       |         |         |        |              |
| Inattentiveness, and   |         |         |        |              |
| Design Alternative     |         |         |        |              |
| Strategies and         |         |         |        |              |
| Techniques for Traffic |         |         |        |              |
| Control. The study was |         |         |        |              |
| conducted by two       |         |         |        |              |
| groups: the Region 2,  |         |         |        |              |
| University             |         |         |        |              |
| Transportation         |         |         |        |              |
| Research Center, City  |         |         |        |              |
| College of New York    |         |         |        |              |
| and the Institute for  |         |         |        |              |
| Transportation         |         |         |        |              |
| Research and           |         |         |        |              |
| Education, North       |         |         |        |              |
| Carolina State         |         |         |        |              |
| University. Working    |         |         |        |              |
| papers were completed  |         |         |        |              |
| for each of those      |         |         |        |              |
| tasks.                 |         |         |        |              |
|                        |         |         |        |              |
| The objective of this  |         |         |        |              |
| research project is to |         |         |        |              |
| study mobile and short |         |         |        |              |
| duration work zone     |         |         |        |              |
| safety with particular |         |         |        |              |
| attention to the       |         |         |        |              |
| identification of work |         |         |        |              |
| zone safety devices,   |         |         |        |              |
| information systems    |         |         |        |              |
| for the reduction of   |         |         |        |              |
| safety and congestion, |         |         |        |              |
| and implementation of  |         |         |        |              |
| innovative techniques  |         |         |        |              |
| to reduce delays and   |         |         |        |              |
| crashes due to work    |         |         |        |              |
| zones.                 |         |         |        |              |
|                        |         |         |        |              |
| The research approach  |         |         |        |              |
| includes a literature  |         |         |        |              |
| search to identify the |         |         |        |              |
| potential technologies |         |         |        |              |
| and information        |         |         |        |              |
| systems for mobile and |         |         |        |              |
| short duration work    |         |         |        |              |
| operations. Potential  |         |         |        |              |
| technologies and       |         |         |        |              |
| information systems    |         |         |        |              |
| were identified from   |         |         |        |              |
| the Transportation     |         |         |        |              |
| Research Board and     |         |         |        |              |
| National Cooperative   |         |         |        |              |
| Highway Research       |         |         |        |              |
| Program reports,       |         |         |        |              |
| international sources, |         |         |        |              |
| Strategic Highway      |         |         |        |              |
| Research Program       |         |         |        |              |
| reports, other State   |         |         |        |              |
| DOT correspondence,    |         |         |        |              |
| and manufacturers and  |         |         |        |              |
| vendors.               |         |         |        |              |
| Recommendations are    |         |         |        |              |
| made to fabricate and  |         |         |        |              |
| implement the Balsi    |         |         |        |              |
| Beam with the          |         |         |        |              |
| assistance of Caltrans |         |         |        |              |
| and the FHWA on        |         |         |        |              |
| selected short         |         |         |        |              |
| duration work zones    |         |         |        |              |
| and implement "Bright  |         |         |        |              |
| Zone Signs and Beacon  |         |         |        |              |
| Wear Safety Vests" to  |         |         |        |              |
| improve work safety    |         |         |        |              |
| and visibility in work |         |         |        |              |
| zones.                 |         |         |        |              |
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| 17\. Key Words         |         | 18\.    |        |              |
|                        |         | Distr   |        |              |
|                        |         | ibution |        |              |
|                        |         | St      |        |              |
|                        |         | atement |        |              |
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| Work zone safety       |         | No      |        |              |
|                        |         | Rest    |        |              |
|                        |         | riction |        |              |
+------------------------+---------+---------+--------+--------------+
| 19\. Security Classif  | 20\.    |         | 21\.   | 22\. Price   |
| (of this report)       | S       |         | No of  |              |
|                        | ecurity |         | Pages  |              |
|                        | C       |         |        |              |
|                        | lassif. |         |        |              |
|                        | (of     |         |        |              |
|                        | this    |         |        |              |
|                        | page)   |         |        |              |
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| Unclassified           | Uncla   |         | 91     | NA           |
|                        | ssified |         |        |              |
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| Form DOT F 1700.7      |         |         |        |              |
| (8-69)                 |         |         |        |              |
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**TABLE OF CONTENTS**

Page

Executive Summary 1

Introduction 1

Research Approach 2

Work Zone Technologies 2

TRB, NCHRP & State Sources 2

Strategic Highway Research Program 4

Law Enforcement 6

Motorist Information, Education & Outreach Programs 7

Review of Work Operations 7

Conclusions 7

Recommendations 9

Introduction 10

Objective 10

Research Approach 11

Short Duration/Mobile Work Zone 12

Manual on Uniform Traffic Control Devices 15

Literature Search 21

TRB, NCHRP & Proceedings 21

State Transportation Agencies 23

Work Zone Technologies 26

Strategic Highway Research Program 34

Balsi Beam 36

Review of Caltrans Balsi Beam 39

Presentations to NJDOT Engineers 40

Methodology and Criteria for Evaluating the New Technologies 41

State Agencies 41

Analysis of the Current NJDOT Practices for Short Duration

and Mobile Work Zones 42

Criteria for Device Functionality In Mobile Work Zones 47

Reduce Exposure to Traffic 47

Warn Motorist/Crew 47

Minimize Crash Severity 48

Provide Separation Between Work Crew and Traffic 48

Improve Work Zone Visibility 48

Guidelines to Eliminate Driver Inattentiveness 51

General Nature 51

Analysis of Work Zone crashes 51

Crash Frequency 52

Crash Severity 52

Crash Location 53

Crash Type 55

Technologies to Reduce Crashes and Improve Driver Attentiveness 57

> Rumble Strips 57
>
> Intrusion Alarms 58

Alternative Strategies and Techniques for Traffic Control Technologies
60

> Technologies 60
>
> Flashing Lights 60
>
> Dancing Diamonds 62
>
> Rotating Lights/Strobe Lights 62
>
> Advanced Warning Signs 64
>
> Variable Message Signs 66
>
> Speed Display Trailers 67
>
> New Dynamic Message Sign Technology 69
>
> Glowing Safety Lights 69

Effectiveness of Police Presence & Enforcement 71

Work Zone Enforcement Technologies 72

Remote Speed Enforcement 72

Work Zone Law Enforcement Functions 74

Guidelines for Use of Extra Enforcement 75

Work Zone Enforcement Legislation 78

Education and Awareness Programs 80

Worker Education Programs 81

Program Implementation 82

CB Wizard Systems 83

Work Zone Evaluation Methods 83

Conclusions 86

Recommendation 91

**Table of Figures**

Figure 1 Typical Work Zone 14

Figure 2 Mobile Operations on the Shoulder 17

Figure 3 Mobile Operations on Two Lane Road 18

Figure 4 Mobile Operations on Two Lane Road Using Flagger 19

Figure 5 Mobile Operations on Multi-Lane Road 20

Figure 6 Balsi Beam Being Rotated from Side to Side 38

Figure 7 Pothole Patching 44

Figure 8 Shoulder Sweeping Operation 44

Figure 9 Landscape spraying operation on outside shoulder 45

Figure 10 Landscape Spraying Operation on inside shoulder 45

Figure 11 Location Distribution of Work Zone Crashes 54

Figure 12 Road Type Distribution for all Work Zones 54

Figure 13 Texas DOT Flashing Lights 61

Figure 14 Dancing Diamond Lights 63

Figure 15 Typical Advanced Warning Signs 65

Figure 16 Typical Variable Message Sign 68

Figure 17 Speed Display Trailer 68

Figure 18 Scotchlite Technology 70

**Table of Tables**

Table 1 Criteria satisfied by selected work zone devices/equipment 50

### Table 2 Major Studies Concerning Crash Characteristics 56

### Table 3 Coverage of Crash Characteristics in Various Studies 56

**EXECUTIVE SUMMARY**

**Introduction**

This report documents and summarizes the study "Identification of
Traffic Control Devices for Mobile and Short Duration Work Operations,"
for the New Jersey Department of Transportation. The study was conducted
in three tasks: 1. Literature Search, 2. Evaluation Criteria and
Analysis, and 3. Identify Guidelines to Eliminate Driver
Inattentiveness, and Design Alternative Strategies and Techniques for
Traffic Control. The study was conducted by two groups: the Region 2,
University Transportation Research Center, City College of New York

and the Institute for Transportation Research and Education, North
Carolina State University. Working papers were completed for each of
those tasks.

The objective of this research project is to study mobile and short
duration work zone safety with particular attention to the
identification of work zone safety devices, information systems for the
reduction of safety and congestion, and implementation of innovative
techniques to reduce delays and crashes due to work zones. The specific
objectives are to:

-   Identify state-of-the art work zone safety technologies to improve
    worker safety in mobile work zone and short term maintenance
    operations,

-   Identify information systems for work zone traffic control to reduce
    delays and crashes,

-   Identify "best practices" for the use of law enforcement to improve
    work zone safety,

-   Identify key issues to be considered from public outreach and
    information systems.

-   The identified work zone safety items will provide improvements for
    maximum protection of the motoring public, protection of exposed
    workers in the work zone and of workers in the set up of the work
    zone, and will meet the current standards established by internal
    policies of the NJDOT.

**Research Approach**

The research approach includes a literature search to identify the
potential technologies and information systems for mobile and short
duration work operations. Potential technologies and information systems
were identified from the Transportation Research Board and National
Cooperative Highway Research Program reports, international sources,
Strategic Highway Research Program reports, other State DOT
correspondence, and manufacturers and vendors. The identified
technologies and information systems were researched to obtain users and
technical information on their effectiveness.

For this study, mobile and short duration work zones are defined as work
operations that move along the pavement or shoulder intermittently or
continuously, with frequent stops or one fixed area where the work
operations require a short time to complete. In all of these situations,
extensive protection systems would not be practicable for the completion
of the work or traffic disruption.

The Manual on Uniform Traffic Control Devices provides uniform standards
for safety protection of workers and traffic control during work
operations. The manual suggests signs, light boards, arrow panels, and
truck mounted attenuators in a caravan of vehicles to provide
state-of-the art protection for exposed works, warn and alert motorists,
and provide traffic control around the work area.

**Work Zone Safety Technologies**

**[TRB, NCHRP and State DOT Sources]{.underline}**

This literature search focused on safety technologies for mobile and
short duration work zone safety technologies from Transportation
Research Board and National Cooperative Research Program publications,
FHWA, State DOT and other agency publications which include web sites of
most national safety organizations. The search identified nine devices
which are used by State agencies or have the potential for use in mobile
and short duration work zones. The devices are:

-   Fluorescent/Bright Signs

-   Reflectorized/Bright Suits and Vests

-   Drone Radar and Speed Indicator/Displays

-   Remotely Operated Autoflagger

-   Truck Mounted Attenuators and Message Boards

-   CB Wizard Alert System

-   Rumble Strips

-   Intrusion Alarm

-   Lane Merger System

The TRB and NCHRP literature indicates that State DOTs use the MUTCD and
caravan approach to mobile and short duration work zone safety
situations. Texas DOT noted operational problems that included the
improper use of arrow­boards, the lack of uniform procedures for freeway
entry and exit, large spacing between caravan vehicles, and unnecessary
lane blockage by the caravan. The recommended solutions to the problems
are improved communications, ef­fective advance signing, controlled
caravan length, caravan positioning proce­dures observed during certain
operation:, and modifications to procedures ob­served in others. Missouri
DOT tested three traffic control devices: ­white lane drop arrows, orange
rumble strips, and the CB wizard alert system-were tested for their
effectiveness in improving merging and reducing speed and speed variance
at an interstate highway work zone. All three devices appear to be
effective for improving safety in work zones.

The States DOTS of Kansas, Nebraska, Iowa, and Missouri conducted a
pooled-fund study of innovative devices designed to improve the safety
and efficiency with which highway maintenance is conducted. In the state
of Kansas, a total of nine devices were evaluated, including lighted
raised pavement markers, CB-radio warning systems, and radar-triggered
speed displays. All of the products showed potential for improving work
zone safety and operations.

An NCHRP study focused on human response to warning lights which varied
by the type of light both in closed field and operational tests. It was
found during research that no one light is maximally effective in both
transmitting information and gaining attention. Therefore several of the
lighting recommendations combine the two types of light in order to
ensure optimum information transmission and conspicuity. Some of the
devices like shadow vehicles were found to be very effective in
producing desired results but involved substantial costs as well.

The Caltrans Worker Safety program includes construction and maintenance
worker safety orientation and instruction, the use of protective
vehicles -- shadow vehicles, barrier vehicles and advance warning
vehicles for all work zones and a District Driver Training Program to
eliminate employee preventable vehicle accidents.

The New York Sate Department of Transportation^(5,^ has initiated
Highway Work Zone Safety Awareness bulletins, partnered with the New
York State Police and identified specific features for improved mobile
and short duration work zones. The agency identified six intrusion
countermeasures: increased police enforcement, reduced channelization
spacing, enhanced flagger stations, rumble strips, reduced speed limits,
dynamic message signs, and drone radar.

**Strategic Highway Research Program**

The Strategic Highway Research Program (SHRP) was initiated to improve
the safety of workers, improve efficiency of work operations and improve
traffic control. The primary emphasize of SHRP was work zone safety
concepts and research of applicable devices.

Of the ten initial devices researched, tested, and developed by SHRP,
the Flashing Stop/Slow Paddles is the only device with a potential for
short duration and mobile work zone traffic control, and therefore
worker safety. The NJDOT has approved this device for use by maintenance
forces. However, the device is clumsy, heavy and requires frequent
battery changes. An initial evaluation indicates that the device is
somewhat effective for traffic control and worker safety.

Recently, SHRP researched five devices that have the potential for
increased work efficiency, and improved worker safety by eliminating
direct worker exposure to traffic and mitigating errand vehicles. The
five devices which are discussed the report are:

-   Cone Shooter

-   Automated Pavement Crack Sealers

-   Automated Debris Removal Vehicle

-   Balsi Beam

-   Robotic Highway Safety Markers.

All of the above five devices appear to have some practical application.
However, the Balsi Beam has the greatest potential for protecting
exposed workers in short duration work operations. The beam provides a
positive protection from errand vehicles and is crash worthy as tested
by NCHRP criteria. Unlike portable concrete median barrier which is time
consuming and labor/equipment intensive to set up, and requires a 42
inch clear zone between the barrier and the worker, the Balsi Beam can
be set up in less than 10 minutes and requires no clear zone between the
beam and workers. The California Department of Transportation is
presently implementing the barrier for specialized concrete construction
and bridge repair operations on high speed interstate highways. The beam
can be used in maintenance operations wherever workers are exposed to
traffic in a limited area for several hours. No workers have been killed
or injured while working behind the beam.

**California Balsi Beam and Presentation**

The researchers met with California Department of Transportation
engineers to observe the operation of the Balsi Beam and talk to
Caltrans maintenance workers. The Caltrans is implementing the second
generation prototype beam with a bridge and concrete repair crew on
Route I-80 between Marysville and Reno, NV.

Caltrans uses the beam for medina barrier repairs, bridge deck patching
and repairs, slab replacement and joint repairs, installation of bridge
sealers and guiderail and parapet repairs.  The beam is used in
conjunction with other safety equipment - -  TMAs, trucks, signs and
safety set up .   The bridge maintenance crew and foreman were very
enthusiastic about using the beam.  The crew is able to use air
compressors, bobcats and other equipment in the work area of the beam. 
Suggestions have been made to incorporate some of the equipment on the
beam-tractor to make the beam a multi-functional piece of equipment. \
\
Essentially, Caltrans, Division of Equipment, designed the beam with
some assistance from TTI and funding from the FHWA.  Caltrans fabricates
and builds their own trucks and large equipment for maintenance, so they
have extensive equipment design and fabricating experience.  Caltrans
and the FHWA would like to implement the beam in the east coast DOTs.   
At this time, Caltrans does not have the resources to demonstrate the
beam throughout the country, and would like other State DOTs to be
involved in implementation.  The researchers believe this is an
opportunity for NJDOT to improve worker safety, be a showcase and assist
the FHWA for the implementation of the beam in the eastern states. 

The researchers presented the information on the Balsi Beam and a
PowerPoint presentation to Region South and Region North Maintenance
workers and engineers. Both regions were interested in the potential for
the beam to protect workers. However, Region North has the best
application for the beam on bridge and concrete repair projects along
Route I-80 in Northern New Jersey.

**Law Enforcement**

In the report, "[The Use of Uniformed Police Officers]{.underline}", the
FHWA recommends the presence of uniformed police officers on Federal-aid
highway work zones. It further recommends the use of automated
enforcement and intrusions alarms as well as uniformed police officers
to improve traffic safety at highway work zones. Our literatures search
indicates that most State DOT s have programs and policy regarding the
use of uniformed police officers at highway work zones.

**Motorist Information, Education and Outreach Systems**

Motorist Information, Education and Outreach Systems are important tools
for State DOTs. Most DOTs and the FHWA have specific programs to inform
the public and train workers.

**Review of Work Operations**

The researchers conducted five field observations of mobile and short
duration work operations to analysis and compare current maintenance
work zone operations with the MUTCD and other agencies, as well as
interviews with work zone safety personnel. The safety for mobile
operations of pothole patching, sweeping, spraying and mobile patching
was in accordance with MUTCD requirements. Workers requested improved
devices such as strobe lights and improved reflective materials for
signs to get driver's attention.

**Conclusions**

The objective of the research project was to study mobile and short
duration work zone safety. The objective was achieved successfully by
suggesting existing and new measures, techniques and devices to better
catch the driver's attention, improve traffic control within work zones,
and recommendations to reduce delays and crashes due to work zones.

Devices and technologies were identified from information from TRB,
NCHRP and other State DOT resources sources. These devices and
technologies are being used or tested by State DOTs, and have the
potential to improve the safety of exposed workers and the motoring
public. The Safe Lites company produces "Bright Zone Signs and Beacon
Wear Safety Vests" with a patented "GlowSkin" technology. This
technology will improve worker visibility and safety in short duration
work operations.

Five new SHRP products for the improved safety of workers and the
motoring public were identified for potential implementation by the
NJDOT. These devices and vehicles remove or enclose exposed workers in
the work area by placing them in vehicles or behind fixed barriers. The
Balsi Beam as developed and implemented by the California Department of
Transportation and the FHWA, has the potential to improve safety of
workers in short duration work operation in New Jersey.

The FHWA recommends the presence of uniform police officers in highway
work zones. Many State DOTs have programs to train and coordinate police
efforts for highway work zones. Motorist Information, Education and
Outreach Systems are important tools for State DOTs. Most DOTs and the
FHWA have specific programs to inform the public and train workers.

Based on the literature search and field inspections of mobile and short
duration work zones, interviews with NJDOT personnel and the literature
search of the cause of work zone accidents, the following conclusions
and recommendations are presented:

-   Most NJDOT work zone crashes are caused by careless driving,
    speeding and motorist inattention cause accidents, which are similar
    causes to crashes in work zones from the literature and other
    agencies. The most significant cause is motorist inattention to the
    work zone system and traffic conditions.

-   NJDOT mobile and short duration work zones meet the safety standards
    for design and application specifications for traffic control during
    highway maintenance by *Manual on Uniform Traffic Control Devices
    (*MUTCD).

-   Safety devices should be selected to reduce traffic speed through
    work zones, improve motorists' recognition of work zone hazards, and
    improve motorists' attention to signs and the work zone.

-   Any new safety devices for mobile and short duration work zones
    should be implemented in conjunction with worker safety training,
    and public safety and education programs.

**Recommendations**

The NJDOT should fabricate and implement the Balsi Beam with the
assistance of Caltrans and the FHWA on selected short duration work
zones.

The NJDOT should implement "Bright Zone Signs" to improve work safety
and visibility in work zones.

The researchers propose to develop a work plan to prepare a licensing
agreement with Caltrans, prepare plans and specifications for bidding,
investigate bidding and fabrication schemes such as fabrication at a
facility in California, inspection and engineering expertise during
fabrication, delivery of the beam, operation training and implementation
studies with NJDOT engineers.

##  

## ***INTRODUCTION***

Work zones are a necessary part of meeting the needs of our nation's
aging transportation infrastructure. With the highway infrastructure
getting older and requiring consistent maintenance, it is believed that
there will be more work zones in the future. These work zones coupled
with traffic on highways are a major source of future and present
congestion. Due to this congestion, there are more chances of crashes
expected, which is a major cause of concern to both workers and the
traveling public. This increased frequency of work in the work zones
makes it necessary to work at day and nighttime, requiring special
precautionary measures to avoid hazards. It is estimated that work zones
contribute to about 24% of highway delay making people more frustrated
due to loss of time.

The final report documents and summarizes the study: "Identification of
Traffic Control Devices for Mobile and Short Duration Work Operations",
for the New Jersey Department of Transportation. The study was conducted
by two groups: Institute for Transportation Research and Education,
North Carolina State University and the Region 2, University
Transportation Research Center, City College of New York. The study
investigated new technologies and information systems to improve safety
of workers in mobile and short duration maintenance work zones.

**Objective**

The objective of this research project was to study mobile and short
duration work zone safety with particular attention to the
identification of work zone safety devices, information systems for the
reduction of safety and congestion, and implementation of innovative
techniques to reduce delays and crashes due to work zones. The specific
objectives were to:

-   Identify state-of-the art work zone safety technologies to improve
    worker safety in mobile work zone and short term maintenance
    operations,

-   Identify information systems for work zone traffic control to reduce
    delays and crashes,

-   Identify "best practices" for the use of law enforcement to improve
    work zone safety,

-   Identify key issues to be considered from public outreach and
    information systems.

Research Approach

This study was conducted in three tasks: 1. The literature research
focused on the identification, evaluation and recommendations for the
implementation of technologies and safety devices for highway
maintenance workers and motoring public, 2. The development a proposed
methodology and criteria for measuring and evaluating the selected new
technologies and Information systems, and the analysis of the current
NJDOT practices for short duration and mobile work zone operations, and
3. The identification of guidelines to eliminate driver inattentiveness,
design alternative strategies and techniques for traffic control. The
three tasks are documented in three Working Papers which were prepared
during the first year of the study. This document summarizes the three
working papers. The reader should refer to the working papers for source
references.

The literature research focused on safety technologies, motorist
information systems, law enforcement, and outreach and education systems
for the motoring public. A concentrated effort was made to search for
mobile and short duration work zone safety technologies which would be
used in field evaluation tasks. The research team searched extensively
through many sources of information to gather the relevant material.
Among the considerations were the websites of State DOT's,
Transportation Research Board (TRB), Strategic Highway Research Program
(SHRP), Federal Highway Authority (FHWA) and Texas Transportation
Institute (TTI). Several of publications such as Better Roads, Roads &
Bridges and Public Works Magazine were searched for relative articles.

The methodology and criteria for measuring and evaluating the selected
new technologies and Information systems was developed from existing
methods and criteria which were researched in the literature. The method
of evaluation consists of using the selected device on appropriate work
zones and includes feedback regarding the ease of use and any problems
with its use by maintenance workers. The guidelines to eliminate driver
inattentiveness, and the alternative strategies and techniques for
traffic control were identified from the literature. The guidelines were
developed from other state DOT sources and practices.

Short Duration and Mobile Work Zone

A work zone is an area of the traveled way where highway construction,
maintenance, or utility-work activities are occurring. A work zone is
generally marked by signs, channelizing devices, barriers, pavement
markings, and construction/maintenance work vehicles. It extends from
the first warning sign or flashing lights on a vehicle to the end of
roadwork sign or the last traffic control device. A work zone may be for
short or long durations and may include stationary or moving activities.
A typical work zone is shown in Figure 1. The work zone activities can
be categorized into the following:

-   Long-term stationary activities: It consists of highway construction
    such as building a new bridge, adding travel lanes to the roadway
    and extending an existing roadway.

-   Mobile highway maintenance activities: It consists of highway repair
    work such as crack sealing and pothole repair etc.

-   Short-term stationary activities: It consists of utility work such
    as repairing of electric, gas, or water lines on the highway.

Mobile work zones can be further categorized as:

-   Intermittent Mobile Operations: These operations like litter
    cleanup, pothole patching, or utility operations, involves frequent
    stops and is similar to stationary operations.

-   Continuous Moving Mobile Operations: These operations include work
    activities in which workers and equipment move along the road
    without stopping (mowing, pavement striping, street sweeping, or
    herbicide spraying), usually at slow speeds.

+-----------------------------------------------------------------------+
| ![](media/image2.png){width="5.572916666666667in"                     |
| height="3.8020833333333335in"}                                        |
+-----------------------------------------------------------------------+
| ##### The Five Defined Areas of the Common Work Zone                  |
+-----------------------------------------------------------------------+

#### Figure 1: Typical Work Zone

######## **Manual on Uniform Traffic Control Devices** 

Part VI of the *Manual on Uniform Traffic Control Devices (*MUTCD)
provides the design and application specifications to meet the special
demand for uniform standards for traffic control during construction and
maintenance operations on streets and highways in the United States.
Temporary traffic control devices (cones and other channelization
devices) and advanced warning signs (flagger ahead and lane closure) are
used to direct traffic around construction zones. The criteria for
design will vary based on environmental conditions such as illumination,
weather, traffic speed and other factors of consideration. Although each
work zone will have individual traffic control plans based on the type
and location of worksite, all traffic control plans will have
similarities that are inherent to every work zone.

There are four typical applications of short duration/mobile operations
described by the MUTCD. These are listed below, and illustrated in the
attached diagrams.

1.  Mobile operations on the shoulder (TA-4) Shown in Figure 2

2.  Mobile Operations on a two-lane road (TA-17) Shown in Figure 3

3.  Mobile operations on a two-lane road using flaggers (TA-13) Shown in
    Figure 4

4.  Mobile operations on a multilane road (TA-35) Shown in Figure 5

**Typical Applications for Temporary and Mobile Operations (MUTCD Part
VI)**

**[Mobile operations on the shoulder (TA-4)]{.underline}**

This operation requires the following equipment:

-   Adequate traffic control signs describing Road work ahead.

-   Optional arrow panel

-   Optional Truck mounted attenuator (TMA)

-   Shadow vehicle with "shoulder work" sign

**[Mobile Operations on a two-lane road (TA-17)]{.underline}**

This operation requires the following equipments.

-   Shadow vehicle with optional arrow panel

-   Sign with appropriate work type

-   Optional Truck mounted attenuator

**[Mobile operations or Temporary Road closure on a two-lane road using
flaggers (TA-13)]{.underline}**

This applies to road closures not exceeding 20 minutes during the
daytime.

This operation requires the following equipments.

-   Flagger

-   Signs

-   Optional Truck mounted attenuator

-   Provide adequate buffer space depending on the speed limit.

**[Mobile operations on a multilane road (TA-35)]{.underline}**

This operation requires the following equipments.

-   Arrow panels

-   Adequate traffic control signs.

-   Shadow vehicles with "lane closed" sign

The typical applications figures are provided in the following pages.
The figures show the position and type of equipments to be used in
temporary and mobile operation. All work zones should strictly adhere to
the MUTCD requirements regarding signs and equipment during a work zone
operation.

![](media/image3.png){width="5.995833333333334in"
height="7.748611111111111in"}

**Figure 2: Mobile operations on the shoulder**

![](media/image4.png){width="5.996527777777778in"
height="7.853472222222222in"}

**Figure 3: Mobile Operations on a two-lane road (TA-17**)

![](media/image5.png){width="5.993055555555555in"
height="8.075694444444444in"}

**Figure 4: Mobile operations on a two-lane road using flaggers**

![](media/image6.png){width="5.991666666666666in"
height="7.8694444444444445in"}

**Figure 5: Mobile operations on a multilane road (TA-35)**

###### LITERATURE SEARCH

The literature research focused on safety technologies, motorist
information systems, law enforcement, and outreach and education systems
for the motoring public. A concentrated effort was made to search for
mobile and short duration work zone safety technologies which would be
used in field evaluation tasks. A list of researched organizations,
agencies and web sites is shown in the bibliography.

**TRB, NCHRP and Proceedings Literature**

During 1999, the Departments of Transportation from the states of
Kansas, Nebraska, Iowa, and Missouri conducted a pooled-fund study of
innovative devices designed to improve the safety and efficiency for
highway maintenance work zones. In the state of Kansas, a total of nine
devices were evaluated, including lighted raised pavement markers,
CB-radio warning systems, and radar-triggered speed displays, among
others. All of the products showed potential for improving work zone
safety and operations. Some of the products require further development
before they can be recommended for widespread deployment. The four
products which appear to show the most promise were orange removable
rumble strips; the Vertical SafetyCade \-- designed to replace the
reflectorized drum, radar -- triggered speed display, and an
experimental configuration of Lightguard lighted raised pavement markers
used to delineate a crossover in an interstate work zone. In all cases,
pneumatic hoses were used to collect the data. In most cases, one to two
days of data were collected before and after device installation.

The University of Kansas evaluated three traffic control devices: ­white
lane drop arrows, orange rumble strips, and the CB wizard alert system.
The devices were tested for their effectiveness in improving vehicle
merging and speed reduction and speed variance at an interstate highway
work zone in Missouri. Results of implementing the white lane drop
arrows and the CB wizard alert system indicate decreases in the
percentage of vehicles in the closed lane, mean speed, and speed
variance. It also appears that the CB wizard alert system may be more
effective than the white lane drop arrows. The CB wizard alert system in
conjunction with the orange rumble strips did show similar reductions,
but they were much smaller in comparison to the CB wizard alert system
alone.

Problem areas identified during the observation of five moving
maintenance operations on Texas urban freeways are discussed in a TRB by
Faulkner. The operations included striping and the installation of
raised pavement markers. The identified problem areas were grouped into
two categories: problems related to freeway design and operational
problems. Problems related to freeway design occur at en­trance and exit
ramps and major interchanges or result from horizontal and vertical
curvature. Operational problems include the improper use of arrow­boards,
the lack of uniform procedures for freeway entry and exit, large spacing
between caravan vehicles, and unnecessary lane blockage by the caravan.
The recommended solutions to the problems are improved communications,
ef­fective advance signing, controlled caravan length, caravan
positioning proce­dures observed during certain operation:, and
modifications to procedures ob­served in others.

This comprehensive research report published by TRB was developed due to
the growing concern of increasing frequency of hazards during moving and
short-term work zone operations. The research was very thorough and
effective in a way that it encompassed different possible formations of
mobile maintenance operations. Eleven categories of short-term and
moving work zones contained corresponding traffic control devices,
vehicle warning light systems and driver actions respectively. Though
studies supported traffic control devices (TCD) applications and
guideline development, it was also found that accident reduction was the
ultimate measure of device effectiveness.

This research mainly focused on human response to warning lights varied
by the type of light both in closed field and operational tests. It was
found during research that no one light is maximally effective in both
transmitting information and gaining attention. The reason for this was
that rotating and strobe lights, which were effective in getting
driver's attention, were not as useful in providing speed and closure
rate information especially when the service vehicle was stopped.
Conversely flashing lights, which worked really well for giving speed
info, were not effective in providing clear clue of working zone to
drivers from long distances. Therefore several of the lighting
recommendations combine the two types of light in order to ensure
optimum information transmission and conspicuity.

Apart from the findings related to different types of lights
functioning's, cost benefit analysis was developed to aid in making some
of the decisions. Some of the devices like shadow vehicles were found to
be very effective in producing desired results but involved substantial
costs as well. Therefore separate cost-effectiveness criteria were
included as a basis for agency-specific decisions regarding its use.

In a research study by the Texas Transportation Institute, potential
hazards associated with mobile and short duration work zones, as well as
the probable underlying causational factors were identified by focus
groups and field observations. In addition, a survey of state
transportation agencies was conducted to determine current practices.
The research study identified four primary hazards: motorist behavior,
motorists' comprehension, and worker exposure and vehicle conflicts.

**State Transportation Agencies**

The goals of the California Department of Transportation (Caltrans)
Highway Worker Safety Program are to: Improve worker safety, reduce
accidents, minimize night work, increase public awareness and use
protective vehicles, equipment and safety apparel. In addition, In 1998
Caltrans initiated a California Highway Worker Campaign to increase
public awareness of work zone safety. The Caltrans Worker Safety program
includes construction and maintenance worker safety orientation and
instruction, the use of protective vehicles -- shadow vehicles, barrier
vehicles and advance warning vehicles for all work zones and a District
Driver Training Program to eliminate employee preventable vehicle
accidents.

The objective of the District Driver Training Program is to eliminate
preventable vehicle accidents. To meet this objective, two programs are
undertaken - one of prevention and one of cure. The prevention consists
of screening the driving record of each potential employee who could be
expected to drive a vehicle as part of the employee\'s work and
providing Defensive Driving Training. The cure program is a refresher
driver training (a minimum of three hours) every four years for
employees who drive on state business and appropriate disciplinary
action for problem drivers of state equipment. Caltrans is also working
with the California Association of Safety Educators to develop a
curriculum, including a video tape, for use in more than 900 driver
education classes statewide. This ongoing program educates new
generations of drivers in how to drive safely near work zones.

Caltrans initiated improved safety equipment such as orange signs and
cones with improved reflectorized sheeting, and change message signs to
provide additional awareness to the public. Improved safety apparel was
also initiated for workers. To reduce worker exposure, specialty
equipment such as liter machines, cone trucks crack sealing vehicles and
spray outrigger vehicles are being used.

California Highway Patrol officers are used on specific work zones to
reduce speed of the traffic. This program has been very effective in
enhancing highway worker safety.

The New York Sate Department of Transportation has initiated Highway
Work Zone Safety awareness bulletins, partnered with the New York State
Police and identified specific features for improved mobile and short
duration work zones. The NYSDOT initiated six intrusion countermeasures:
increased police enforcement, reduced channelization spacing, enhanced
flagger stations, rumble strips, reduced speed limits, dynamic message
signs, and drone radar.

**WORK ZONE TECHNOLOGIES**

Workers in short-term maintenance work zones are placed in a
particularly hazardous position. Short-term and mobile maintenance work
zones are typically located on high-speed roads; with traffic control
installed each day in the morning and removed by dusk. Since these work
zones are in place only for a short time, drivers do not expect to
encounter them. Regulatory speed limits cannot be lowered at the sites,
and it is difficult to get law enforcement agencies to regularly patrol
temporary work zone sites.

**Fluorescent Signs for Work Zones**

The Iowa DOT is using fluorescent signs for their mobile work zone
operations. These illuminated signs (fluorescent being the background)
were developed to get the driver's attention approaching the work zones.
The illuminated part may be yellow or green and gives a clear visibility
to motorists. These signs are mounted on the back of trucks. The DOT
claims that they are producing good results.

**Advanced Warning Signs**

The Virginia Department of Transportation (VDOT) is continuously
striving to improve the flow of traffic as well as to protect workers
and motorists in work zones. By using an advanced warning sign that is
easily understood by motorists, both motorists and workers benefit. VDOT
and several other state departments of transportation have expressed
interest in modifying the advanced warning signs for work zone
operations. The advanced warning sign is intended to alert drivers and
to prepare drivers to stop (if necessary) prior to reaching work zone
operations. For example the construction vehicle sign warns drivers that
the truck they are following is a construction vehicle and may leave the
lane to enter an active work area.

Flashing arrow boards warn drivers that the lane they are traveling in
is closing ahead and a lane change is required. The arrow direction will
indicate which lane is open for travel. Similarly, when only the four
corners of the board are flashing, drivers must use caution, but do not
change lanes. This light pattern is also used when work is on the
shoulder of the roadway.

Variable Message Signs

Variable message signs (VMS) are traffic control devices used to provide
motorists en-route traveler information. They are commonly installed on
full-span overhead sign bridges, post-mounted on roadway shoulders,
trailer mounted for work zones and overhead cantilever structures. For
work zones, the objective of providing the information is to allow the
motorist time to avoid an incident, prepare for unavoidable conditions,
or to give travel directions. For all information displayed the goal is
to have a positive impact on the motorist's travel behavior. VMS are
designed to affect motorist behavior to improve traffic flow, safety and
operations. Changeable messages signs (CMS) or portable VMS are intended
to operate in a location for a short period of time and then be moved to
a new location or stored until needed again. Variable message sign
technology includes: flip disk, light emitting diode, fiber optic and
hybrid of several technologies.

Several manufacturers are working to solve the problem of driver
inattentiveness to variable message signs by developing systems that use
the signs to display messages based on real-time measurements of traffic
conditions. One such system is *Adaptir (Automated Data Acquisition and
Processing of Traffic Information in Real-Time)*, a technology developed
by the Scientex Corp. with support from the Federal Highway
Administration (FHWA) and the Maryland State Highway Administration.

The Adaptir system measures traffic speeds using Doppler radar, the same
technology used by police to detect speeders. Traffic speeds are
measured at several points within and upstream of a work zone. The data
are then sent to a central control system, which analyzes the data to
pinpoint patches of traffic congestion and delay and then selects the
appropriate prerecorded message to post on a variable message sign- -or
series of signs\--just upstream of the site. The messages prepare
motorists for actual traffic conditions ahead. For example, if traffic
is extremely slow in the work zone, a variable message sign upstream of
the work zone might warn of a 10-minute delay ahead; a second sign might
then warn drivers to slow to 55 km/h (35 mi/h). If traffic speeds
decrease further, indicating worsening congestion, the system would
automatically change the signs to indicate an even longer delay and
advise of slower speeds ahead. The signs can also be used to suggest
alternate routes or tell drivers to tune in to a highway advisory radio
station. To emphasize the timeliness of the messages, each sign can also
display the time the message was posted. Drivers armed with information
on traffic ahead are better prepared for changing traffic conditions and
thus more likely to have a safe trip. The economic benefits of reducing
delays and improving safety at a work zone can outweigh the cost of the
Adaptir system by a factor of six or more, according to an economic
analysis conducted by Scientex.

**Truck Mounted Attenuators and Message Boards**

Trucks / trailers can carry different devices to inform motorists of
work zone

presence. Texas Transportation Institute tested a speed control device
placed on the back of a trailer and found it very effective as the
drivers slowed by an average of 5 mph while passing through work zones.

Portable Changeable Message Signs (PCMS) can also be fixed on the top at
the back of trucks or trailers. The message changes with the progress of
work going on in the construction zone to provide real-time information.
The message can be varying speed limit or some warning message like
change of lane, congestion ahead etc. alerting the drivers to slow down,
because of highway maintenance going ahead. Energy Absorption Systems
tested the first truck-mounted impact absorption device that can
withstand the force of up to 4,410lbs, traveling at up to 62 miles/hr,
meeting both mandatory and optional National Cooperative Highway
Research Standards.

**Drone Radar and Speed Display Trailer**

The purpose of Drone Radar is to reduce speed in work zones resulting
safer

work areas. Drone radar is generally placed on portable changeable
message sign/signs (PCMS) and since PCMS has the power, it activates
Drone Radar. Radar alerts the inattentive drivers before approaching the
transition area. A study by Dr. Patrick McCoy showed that radar speed
displays have been effective, although their working depended on their
proximity to work zone area. The Ohio DOT and Massachusetts DOT are
employing this device and have found it to be satisfactory. The Virginia
DOT is also using Unmanned (Drone) Radar detectors to inform drivers
approaching the work zone.

Speed display trailer studied by TxDOT features a 24-inch LED display
and uses Ka-band radar to detect oncoming vehicles. The display has a
strobe lamp that flashes when a vehicle is detected traveling over a
preset speed threshold. This feature is intended to simulate the
operation of photo radar, possibly decreasing speeds through the threat
of automated enforcement. During this evaluation, the speed threshold
for the strobe light was set at 75 mph. The display also has a 130 dB
siren that can be activated by vehicles traveling over a preset speed.
This option is intended to warn workers when an extremely high-speed
vehicle is approaching.

This device proved to be effective in short term/mobile operation as the
display could be set up in under 10 minutes. The controls were easy to
operate, and TxDOT crews that have used the device have reported no
maintenance problems.

**Flashing Lights**

Research sponsored by the Texas Department of Transportation (TxDOT) and
conducted by the Texas Transportation Institute (TTI) has revealed
helpful techniques that improve safety for workers and increase
visibility of work zones for motorists. In a general scenario, the
indication of a work zone ahead is given to the drivers by flashing
yellow warning signals or a sign telling to move from one lane to the
other. A new method of warning drivers of approaching work zones is
proving to be safer and easier to understand from greater distances. The
approach was developed as a part of a TTI research project that was
sponsored and implemented by TxDOT. It utilizes a series of synchronized
flashing lights attached to the drums that form a lane closure taper.
The flashing lights illuminate in a sequence from the beginning to the
end of the taper. According to closed-course studies at TTI\'s Riverside
Campus in College Station and roadway tests in Houston, drivers
responded more positively to the synchronized flashing light system than
to the normal traffic control setup used at construction sites in Texas.
It was also found that as the synchronized flashing warning light system
was activated, there was a one-fourth reduction in the number of
passenger vehicles 1,000 feet before the lane closure taper.

**Dancing diamonds (lights)**

The Oregon Department of Transportation (ODOT) uses dancing diamond
panel displays as an advance caution device for mobile and short
duration maintenance operations. The panel is a sign with a matrix of
light elements capable of either flashing and/or sequential displays.
Non-directional arrow panel displays are intended as caution displays.
Before 2001, literature lacked significant statistical support for any
one type of caution display. A 2001 Oregon Department of Transportation
(ODOT) study suggested that the + ACI-dancing diamonds are better than
the other caution displays like flashing box. ODOT also found that local
citizens preferred the dancing diamonds to other caution displays.
However, additional research was needed to confirm these findings.

To evaluate the effectiveness of the dancing diamonds and +ACI- flashing
box+ACI- displays, a field experiment was conducted. The results of this
experiment showed that the dancing diamond was associated with a
statistically significant 3 km/h (2 mph) reduction in mean speeds,
whereas the flashing box display was associated with no statistically
significant reduction in mean speeds, indicating that the dancing
diamonds prompt safety near highway work better than the flashing box.

Rotating lights / Strobe Lights

This comprehensive research report published by TRB was developed due to
the growing concern of increasing frequency of hazards during moving and
short-term work zone operations. The research was very thorough and
effective in a way that it encompassed different possible formations of
mobile maintenance operations. Eleven categories of short-term and
moving work zones contained corresponding traffic control devices,
vehicle warning light systems and driver actions respectively. Though
studies supported traffic control devices (TCD) applications and
guideline development, it was also found that accident reduction was the
ultimate measure of device effectiveness.

This research mainly focused on human response to warning lights varied
by the type of light both in closed field and operational tests. It was
found during research that no one light is maximally effective in both
transmitting information and gaining attention. The reason for this was
that rotating and strobe lights, which were effective in getting
driver's attention, were not as useful in providing speed and closure
rate information especially when the service vehicle was stopped.
Conversely flashing lights, which worked really well for giving speed
info, were not effective in providing clear clue of working zone to
drivers from long distances. Therefore several of the lighting
recommendations combine the two types of light in order to ensure
optimum information transmission and conspicuity.

Apart from the findings related to different types of lights
functioning's, cost benefit analysis was developed to aid in making some
of the decisions. Some of the devices like shadow vehicles were found to
be very effective in producing desired results but involved substantial
costs as well. Therefore separate cost-effectiveness criteria were
included as a basis for agency-specific decisions regarding its use.

**Rumble Strips**

In an effort to promote safer conditions in work zones, the Kentucky
Transportation Center, in conjunction with the State of Kentucky and the
Federal Highway Administration (FHWA), sponsored a project to
demonstrate the use of the portable rumble strip at maintenance work
zones across the State. When drivers feel the vibration and hear the
sound caused by the portable rumble strip, they are given a final
reminder that they are about to enter a temporary work area.

Developed by the Strategic Highway Research Program (SHRP), the portable
rumble strip is placed across the road about 100 m (250 ft) in advance
of the work zone. The device causes a vibration in the steering wheel
and a rumble as vehicles pass over it, warning drivers that conditions
on the road will soon become dangerous. The portable rumble strip is
best suited for low-speed roads that carry few heavy trucks. The
portable rumble strip is also easy to use. The device weighs about 34 kg
(75 lb), and one or two workers can deploy it from the back of a pickup
truck.

A number of studies have demonstrated the benefits of shoulder rumble
strips in reducing death and serious injury caused by inattentive
drivers in Run-off-road (ROR) crashes. The methodologies used in these
effectiveness studies and their results vary from state to state, but
all show some measure of crash reduction attributed to the presence of
shoulder rumble strips.

**Intrusion Alarms**

Drivers sometimes fail to notice the signs, cones, and other warnings
that they are approaching a highway work zone. Intrusion alarm developed
under the SHRP provides safety to workers in the work zone either by
audio or visual means, when a motorist intrudes into the work zone.
State of Vermont is using these alarms to inform the workers well before
the danger. Example of audio intrusion alarm is a flashing strobe light,
which activates as soon as a driver by mistake enters in the danger part
of a work zone. The biggest benefit is that the workers get few seconds
to clear out of danger way.

After testing two models of the work zone intrusion alarm, Vermont
AOT\'s research unit purchased a model that uses an infrared beam sent
from a transmitter unit to a receiver unit that also houses the siren.
When a vehicle breaks this beam, the siren goes off. The research unit
picked this model because it was the fastest and easiest to set up.

**STRATEGIC HIGHWAY RESEARCH PROGRAM (SHRP)**

The SHRP was started in 1987 by the U.S Congress in response to a
growing national concern over the condition of the highway system. It
established a 5-year, large-scale, applied research program aimed at
improving the performance, durability, safety, and efficiency of the
Nation's highway system.

The Strategic Highway Research Program (SHRP) was initiated to improve
the safety of workers, improve efficiency of work operations and improve
traffic control. The primary emphasize of SHRP was work zone safety
concepts and research of applicable devices. Tthe Strategic Highway
Research Program (SHRP) identified 10 work zone safety device concepts
that are applicable in work zones; especially for maintenance
activities. There are currently eight manufactured devices available:

> 1\. Salt Spreader Truck-Mounted Attenuator (TMA).\
> 2. Vehicle Intrusion Alarm (discussed above).\
> 3. Queue Detector.\
> 4. Portable Rumble Strip (discussed above)\
> 5. Direction Indicator Barricade.\
> 6. Opposing Traffic Lane Divider.\
> 7. Flashing STOP/SLOW Paddle.\
> 8. All-Terrain Sign & Stand.

The Salt Spreader Truck-Mounted Attenuator is commercially produced and
is marketed exclusively by private industry. The seven other devices,
representing the basic SHRP-developed concepts, are commercially
available and are ready for field use. These include Opposing Traffic
Lane Dividers, Portable Rumble Strip, Flashing STOP/SLOW Paddle,
Direction Indicator Barricades, Vehicle Intrusion Alarms, Queue
Detector, and the All-Terrain Sign Stand with Signs. The other two
devices are the Remotely Driven Vehicle (RDV) and the Portable Crash
Cushion trailer (PCT). The Remotely Driven Vehicle (RDV) is being
evaluated by the Minnesota DOT and is under development. Shorter-length
Portable Crash Cushion trailer (PCT) have been built for FHWA and are
being tested in Alabama, New York, California, and Minnesota.

**Cone Shooter**

The Advanced Highway Maintenance and Construction Technology (AHMCT)

Center has developed a machine that can automatically place and retrieve
traffic cones. This new device can safely and quickly opens and close
busy lanes.

Typical lane configuration uses 80 traffic cones for each 1.5 miles of
lane closure. Usually cones come in size of 36 inches. Caltrans uses a
28-inch cone weighing 10 pounds. Manually only three cones can only be
carried by a worker at a time. Also it is difficult for place cones
during mobile operations. It is slow and dangerous in busy roads. The
cone shooter is meant to reduce injury and cost.

**Automated Pavement Crack Sealers**

One of the frequent maintenance operations involves crack sealing of the
pavements. Sealing of cracks along the pavement is done by mobile
operation. Crack sealing is performed for longitudinal cracks or sealing
of joints between concrete lanes and also random cracks along the
pavement. Hand sealing of longitudinal as well as random cracks consume
more time, involve workers, safety concerns and also lanes closure. The
AHMCT has developed two automated pavement crack sealers: a.
Longitudinal Crack Sealer, and b. Random Crack Sealer. The devices
perform the same operation with greater efficiency and less time. A
typical sealing operation involves a large crew sealing 1.5 to 3 km per
day, while the crew is exposed to moving traffic in adjacent lanes.

**Debris Removal Vehicle**

Roadway litter removal is labor intensive, may expose workers to
traffic, and costs the nation over half a billion dollars a year. To
help make litter removal safer and more efficient, AHMCT has developed
the new litter removal and debris vacuum system. The two vehicles
developed are: a. Automated Litter Bag/Debris Collection Vehicle, and b.
Debris Vacuum System.

Manual retrieving of litter bags and debris can be greatly improved in
terms of efficiency and safety with the introduction of the Automated
Litter Bag/Debris Collection Vehicle developed by the AHMCT Center. The
main goal of the machine is to reduce the number of personnel required
for the operation and keep the worker safely within the vehicle while
still allowing efficient performance.

**Robotic Highway Safety Markers**

All work zone maintenance operation uses traffic control devices such as
cones, signs, safety barrels and barricades. Proper traffic control is
critical in highway work zone safety. Deployment of these devices in
work zone involves labor, consumes time, and poses hazards to workers.
Also for mobile work operations, placement of the devices could be
impossible. In order to efficiently use the devices for work zones, the
department of Mechanical engineering in University

of Nebraska Lincoln has developed a mobile safety barrel robot. The
robotic safety barrels can self-deploy and self-retrieve, removing
workers from this dangerous task. The robots move independently so they
can be deployed in parallel and can quickly reconfigure as the work zone
changes. These devices would be of great advantage in mobile work zones,
where the cones or barrels could move along with the working crew,
saving time and increasing safety to workers.

**Balsi Beam**

The Balsi Beam is a truck mounted, moveable, expandable beam that will
provide positive work zone protection comparable to a fixed concrete
barrier. It is specifically intended to enhance worker safety when
carrying out shoulder repair in work zones adjacent to guardrails, inlet
repair, bridge rails, bridge deck repair, sound walls and other work
where workers are normally exposed to traffic or behind cones in short
work areas for several hours. Usually the shadow vehicle or the truck
mounted attenuator provides protection from rear end collisions; the new
device provides protection from adjacent lane traffic.

Each side of the trailer consists of high-strength steel box and I-beams
section that are capable of extending an additional 15 feet for a total
of 30 feet of secure working area. Using hydraulic power, each beam can
rotate to either side (left or right), depending on which side of the
road a protective barrier is needed. The trailer beams act as a rigid
obstacle to deflect traffic away from maintenance workers.

The Balsi Beam was initiated by the California Department of
Transportation and the Federal Highway Administration to address the
high rate of highway maintenance workers that are killed each year. The
Laborer's Health and Safety Fund indicates that 120 to 130 highway
workers are killed each year in work zones by errand vehicles. The
American Road & Transportation Builders Association indicate that the
fatality rate for highway maintenance and construction workers is 32
people killed for every 100,000 workers. By comparison, the rate for all
construction workers is 13 people killed per 100,000 workers and the
general industry rate is 4 people killed per 100,000 workers. These
terrible statistics indicate the need for a highly mobile device to
protect exposed work zone personnel. Indeed, no such device can be all
encompassing, but any device that reduces highway worker fatalities such
as the Balsi Beam is an important asset to highway workers and the
people who want to protect them.

As a result of a serious accident, Caltrans' Division of Maintenance
investigated various means to protect exposed workers. The Caltrans'
Division of Research and Innovation researched concepts for a protection
system and the Division of Equipment designed and built a mobile work
zone protection device (Balsi Beam) with the assistance of a trailer
manufacturer. The Balsi Beam has its own dedicated tractor truck to
transport it to the worksite at normal highway speeds without the need
for any permits.

![](media/image7.jpeg){width="3.6659722222222224in"
height="1.8027777777777778in"}

Figure 6 The Balsi Beam being rotated from side to side

The Balsi Beam system is highly mobile, highly maneuverable, easily
deployed and is capable of redirecting a ¾ ton pick truck at near NCHRP
TL-3 impact performance levels. Crash tests at TL-2 and near TL-3
indicate that the beam showed no deflections. (Caltrans tests for TL-3
were performed at an angle of 20 degrees and speed of 60 mph.) The Texas
Transportation Institute reviewed and categorized a large number of
highly mobile work zone operations for the functional requirements of
the Balsi Beam. These operations included about two thirds of the total
operations that maintenance workers normally perform.

The device is being implemented in Caltrans' District 4, which serves
the San Francisco Bay area. Caltrans plans to deploy it for more testing
elsewhere in the State. The prototype device cost approximately
\$217,000 to build, but it is expected that cost would drop
significantly when other models are produced. A

patent for the Balsi Beam system is pending.

**Review of Caltrans Balsi Beam**

The California Department of Transportation demonstrated the Balsi Beam
at their Marysville Maintenance yard and conducted a meeting with the
researchers to discuss the development and implementation of the beam.
The beam is being implemented by a bridge repair crew on Route I-80 from
Marysville to Reno, Nevada. This section of the route has many
structures and has mountainous terrain. In good weather, typical traffic
speeds exceed 80 mph. Before implementation of the beam, the crew had
experienced many work zone intrusions by high speed errand vehicles.

The crew uses the beam to protect workers repairing bridge decks,
joints, parapets, concrete approaches and median barrier. Essentially,
any work in a limited area where workers and equipment are concentrated
for a specific task for several hours or one work day. Using improvised
work techniques and small equipment such as a Bobcat to replace a larger
front end loader, the crew is able to provide safe protected work areas
which include a truck with tools, an air compressor and concrete mixer.
Other work techniques provide space for a dump truck to unload material
for patching and repairs. Future modification to the beam trailer will
include tool storage and mounting for a compressor or other such
equipment. Caltrans workers feel secure behind the beam.

The Balsi Beam trailer is driven to the work site; the beam is rotated
to provide protection for the appropriate side and locked into place.
The beam requires about 10 minutes to set-up. The set up of other safety
equipment is typical to the set up time for any lane or shoulder
closure. The beam is accompanied by several dump trucks with TMAs,
signs, light boards, tool storage vehicles and appropriate devices for
closing a lane or shoulder. In special case cones are used in
conjunction with warning signs ahead of the work area. Since traffic
speeds are very high and vehicle intrusion likely, work zone safety is
carefully planed to provide the maximum protection for works and the
safety of the traveling public. The advantage of the beam in such a work
zone is the positive protection of workers in a concentrated area for a
specific task. Indeed, barrels or cones, even behind a dump truck with a
TMA would not afford the secure enclosed wok area.

**Presentations to NJDOT Engineers**

The researchers presented the results of the Caltrans beam demonstration
to maintenance engineers in the Trenton Headquarters, Region North and
Region South. The PowerPoint presentation provided a background of the
beam development, crash test information and pictures showing the
functions of the beam. The researchers provided answers to the
engineers' questions. Most engineers were enthusiastic about the
implementation and safety prospects of the beam for NJDOT operations.

METHODOLOGY AND CRITERIA FOR MEASURING AND EVALUATING THE NEW
TECHNOLOGIES AND INFORMATION SYSTEMS

**State Agencies**

The Texas Transportation Institute conducted a survey of all state
transportation agencies to obtain data on safety operations for mobile
and short duration maintenance. Information, supporting materials and
data were obtained from eighteen agencies. In addition to the survey
responses, focus groups of Texas Department of Transportation field and
supervisory personnel were assembled to identify hazards and to simulate
new ideas and creative concepts that could improve worker and motorist
safety through such work zones. The TTI investigators conducted field
observations of eleven mobile and eighteen short duration maintenance
operations in five districts of Texas.

The TTI survey results indicated the most significant hazards for all
responding agencies were high speed traffic, and inattentive motorists
which resulted in rear end crashes of safety vehicles and errant
vehicles entering the shadow vehicle convey or the work area. Some state
agencies approach the solution to these issues by incorporating advance
warning devices in addition to the standard MUTCD safety. Such devices
and solutions are:

-   brighter or fluorescent signs on shadow vehicles,

-   trail vehicles with speed display boards below the arrow panel,

-   the use of better or additional lighting on shadow vehicles, such as
    solid light bars, blue lights, or light emitting diode(LED) lights,

-   dynamic message boards in advance of the work area, and

-   police to enforce traffic laws.

All of these devices provide the motorist with the optimum warning to
reduce or eliminate crashes and improve worker safety.

The New York State Department of Transportation maintains a work zone
accident data base to track the causes of crashes in such areas. The
annual analysis of these data indicate that rear end accidents of
construction and maintenance vehicles and rear end crashes of motorists
by other motorists is the most common crash. Such crashes are indicative
of speeding and inattentiveness by motorists. The New York Sate DOT has
identified seven intrusion countermeasures for stationary, mobile and
short duration work zones:

-   reduced channelization spacing,

-   enhanced flagger station,

-   rumble strips,

-   reduced speed limits

-   police enforcement,

-   dynamic message signs, and

-   drone radar.

The Center for Transportation Studies at the University of Virginia
studied the characteristics of work zones crashes for all types of work
zones. The results indicate that rear end crashes are the predominate
type of crash. Although no solutions were proposed in the scope of the
study, it clearly indicated that speed and inattentiveness are
contributing factors for such crashes.

**Analyses of the Current NJDOT Practices for Short Duration and Mobile
Work Zone Operations**

The researchers conducted field observations of mobile and short
duration work operations to analysis and compare current maintenance
work zone operations with the MUTCD and other agencies, as well as
interviews with work zone safety personnel. The first group of field
observations was conducted in Region South with personnel from the
Bureau of Employee Safety.

The mobile pothole patching operation consisted of the automated pothole
patching truck, two dump trucks with Truck Mounted Attenuators behind
the patching truck, and the foreman's pickup truck ahead of the patching
truck. The operation occurred on inside northbound lane of U.S. Route
130 in Haddon Township. The operation is shown in Figure 7. A flashing
arrow board, "Road Work Ahead" sign and a Scorpion TMA were mounted on
the rear of both dump trucks. The dump trucks maintained proper distance
between the potholing patching and traffic as the operation rounded
curves and advanced in the straight roadway. A single warning sign was
placed off the right should some distance prior to the operation.

A sweeping operation consisted of the sweeper and a single dump truck on
NJ Route 38 in Mount Laurel. The operation was in the right shoulder.
The flashing light board and sign were similar to the previous
operation. The sweeping operation is sown in Figure 8

During the inspection of the above mobile operations, the NJDOT
inspectors observed an electrical crew preparing for repair work at a
traffic intersection. The electrical crew had not placed warning signs
ahead of their parked vehicle, and failed to wear safety vests. The
NJDOT inspectors discussed safety rules with the crew.

The second group of field observations was conducted in Region North
with personnel from the Bureau of Employee Safety. The observations
consisted of a liter pick up operation which consisted of a dump truck
and dump truck with small TMA, and a landscape spraying operation with
the truck mounted sprayer and a dump truck with a Scorpion TMA on Route
I-280 in West Orange. Both operations were being conducted on the
shoulder. This operation is shown in Figure 9.

A second landscape spraying operation was observed on Route I-78, Scotch
Plains in the insider shoulder. The operation consisted of the sprayer
and two dump trucks each with a Scorpion TMA. The Shadow vehicles rode
in the inside lane to protect the spraying vehicle with straddled the
shoulder and lane. This is shown in Figure 10.

![](media/image8.jpeg){width="4.702083333333333in"
height="3.5395833333333333in"}

Figure 7 Pothole Patching Operation.

.![](media/image9.jpeg){width="4.7375in" height="3.5527777777777776in"}

Figure 8 Shoulder Sweeping Operation

![](media/image10.jpeg){width="5.004166666666666in"
height="3.7527777777777778in"}

Figure 9. Landscape spraying operation on outside shoulder

![](media/image11.jpeg){width="5.084027777777778in"
height="3.8131944444444446in"}

Figure 10. Landscape spraying operation on the inside shoulder.

A short duration work zone was observed on Route I-287, Basking Ridge.
The operation consisted of a pothole patching crew that was filling a
pothole with hot mixed asphalt. Three dump trucks with the Scorpion TMA
were located behind two workers who were shoveling the material from a
dump truck. A foreman's pick up truck was in front of the dump truck.
The two workers were exposed to traffic for a distance of 30 feet
between the attenuator truck and material truck. Traffic was backed up
for a mile or more behind the operation and was moving slowing past the
operation, which precluded taking pictures.

In interviews with the NJDOT personnel from the Bureau of Employee
Support, it was noted that most work zone accidents in New Jersey are
caused by errant motor vehicles. Few work zone intrusions or crashes are
caused by trucks. In their opinion, these accidents at NJDOT work zones
were caused by careless driving, speeding, and inattentiveness of the
motorists to the work zone, other vehicles and signs. Driver
inattentiveness was the most significant cause. The personnel emphasized
the importance of police for all work zone operation because police
encourage motorist to reduce their speed.

The NJDOT personnel emphasized the importance of public education --
outreach and safety programs -- to inform the public on the importance
of work zone safety, and the need to show that workers have families and
need their considerations. Safety programs should include work zone safe
driving instructions in driver's manuals, posters and education for
truck drivers at rest stops, and CB notification for truckers and in-car
notification for motorists in the event of a work zone. Such items will
be discussed in subsequent working papers and tasks for this project.

NJDOT personnel suggested improved advanced warning such as signing
ahead of the work zone, improved lighting such as LED, variable strobes,
and arrow boards that "follow" traffic, and improved work zone planning
to reduce conflicts between various maintenance operations.

**Criteria for Device Functionality in Mobile Operations**

These evaluation criteria for certain devices will provide assistance in
selecting appropriate traffic control devices for worker safety, and the
safe and efficient movement of traffic through mobile and short duration
work zones. From the devices and equipments identified in the literature
report and, depending on the utility and effectiveness, the device
functionality can be classified into five categories as follows:

**[Reduce exposure to the motorists/crew]{.underline}**

Along work zones, the changing driver habits and traffic patterns cause
safety concerns. The device should keep the road users and workers safe,
while at the same time inhibiting traffic flow as little as possible.
The ultimate goal of this criterion is to prevent worker injuries, motor
vehicle accidents, and personal injury to motorists and/or pedestrians.

**[Warn motorists/crew to minimize likelihood of crash]{.underline}**

Maintenance crews in short-term work zones have a frightening job.
Short-term/mobile work zones present special challenges in providing
safe conditions for work crews. In short duration or mobile work zones,
which are only in one place for a short period of time, motorists have
very little chance to develop any expectations about the presence or
layout of the work zone. Workers must perform their repair work while on
constant alert for drivers who disregard or fail to notice the warning
signs to slow down. This study is attempting to identify devices that
would effectively alert drivers to work zone conditions and motivate
them to change the way they drive within the work zone. The traffic
control devices should be able to warn as well as minimize the
likelihood of crash in order to improve worker and driver safety.

**[Minimize severity of crashes once they occur]{.underline}**

An effective traffic control device in a short-term work zone must be
easy to set up and remove without compromising the safety of the
workers. Even though no one device can eliminate all, crash severity can
be minimized by using devices that could absorb the major impact and
reduce exposure to workers. Truck mounted attenuators, crash cushions
and Balsi Beam can serve as devices which satisfy this criterion. The
devices should also provide sufficient visibility to gain driver
attention.

**[Provide separation between work crew and traffic]{.underline}**

Separating traffic from work activities by the use of temporary traffic
barriers, shadow vehicles with truck-mounted attenuators, or similar
devices minimizes risk for both workers and travelers. The need for
positive separation should be based on work zone factors including:

-   Traffic speed and volume

-   Distance between workers and traffic

-   Duration and type of work operations

-   Physical hazards present

**[Improve work zone visibility/presence]{.underline}**

Visibility issues for motorists approaching and driving through highway
work zones is a major concern. Ninety percent of a driver\'s reaction
depends on vision, and vision is severely limited at night or in
inclement weather conditions. Depth perception, color recognition, and
peripheral vision are all compromised after sundown. Conditions such as
fog, rain, snow and dusk also hinder visibility to drivers, therefore
decreasing worker safety. Therefore it is important to provide good
visible traffic control devices and sufficient lighting to the work
zones.

Traffic control devices and delineation treatments need to be effective
in meeting the needs of motorists on various types of highway facilities
under various traffic and lighting condition. Lighting should be used on
traffic control devices such as flashing lights or arrow panels. Glare
must be controlled so as not to interfere with the visibility of the
work zone by drivers and workers.

The work area and its approaches should also be lighted to provide
better visibility for drivers to safely travel through the work zone.
Illumination should be provided wherever workers are present to make
them visible.

The summary of the criteria and initial device performance are shown in
Table 1.

**Table 1 Criteria satisfied by selected work zone devices/equipment**

  ------------------------------- --------------- ------- ------- ------- --------
  **WORK ZONE DEVICE**            **CRITERION**                           

                                  **1**           **2**   **3**   **4**   **5**

  **Truck Mounted Attenuator**                                             

  **Vehicle Intrusion Alarm**                                              

  **Rumble Strips**                                                        

  **All Terrain Sign and Stand**                                           

  **Directional Indicator                                                  
  Barricade**                                                             

  **Flashing Stop/Slow Paddle**                                            

  **Opposing Traffic Lane                                                  
  Divider**                                                               

  **Queue Detector**                                                       

  **Remotely Driven Vehicle**                                              

  **Portable Crash Cushion**                                               

  **Cone Shooter**                                                         

  **Pavement sealers**                                                     

  **Debris Removal Vehicle**                                               

  **Balsi Beam**                                                           

  **Robotic Highway Safety                                                 
  Marker**                                                                
  ------------------------------- --------------- ------- ------- ------- --------

From the above table it is seen that none of the devices fully satisfies
the entire five criteria. But devices such as Truck mounted attenuator,
remotely driven vehicle, and Balsi beam at least partly satisfies all
the criteria.

**GUIDELINES TO ELIMINATE DRIVER INATTENTIVENESS**

**General Nature of Work Zone Crashes**

Past accident-based analyses have provided some knowledge of the general
nature of work zone crashes. However, there is a continuing need for
additional analyses of well-defined and more detailed accident data.
Through better identification of the specifics of the work zone problem,
it is hoped that, ultimately, work zone safety will be enhanced
considerably. There is a continuing need for information on the number
of vehicles involved, the type of crash and the manner of collision,
vehicle maneuvers before the crash, and the first and most harmful
events. If these general crash descriptors could be analyzed by zone
type, such information would provide a better understanding of the
extent to which a crash can be attributed to vehicle flow and the path
provided to an individual vehicle. This analysis would be an initial
step in setting priorities for treatment development and direction.

**Analysis Of Work Zone Crashes**

Work zone related crashes continue to increase every year across the
nation, thus the safety of road users and workers has become a top
priority for transportation agencies. Work zones tend to cause hazardous
conditions for drivers and construction workers since they generate
conflicts between construction activities and traffic. Numerous
innovations in temporary traffic control materials and techniques have
been developed and deployed in recent years.

Many studies seem to indicate that the introduction of work zones lead
to an increase in accident rates, although that pattern is dependent on
traffic and geometric conditions, traffic control devices, length of
work zone, weather, lane closure strategy and other aspects of the work
zone environment. The increase in crash rate at work zones may be due to
several reasons including disruption of traffic due to closed lanes,
improper lane merging maneuvers by drivers, and inappropriate use of
traffic control devices

**Crash Frequency**

Studies related to work zones revealed that crash rates at work zones
were higher than at non--work zone locations. They also indicated that
crash rates depend on the type of traffic control device used. In a
construction zone crash study conducted by Hall and Lorenz, crashes
during construction increased by 26 percent compared with crashes in the
same period in the previous year when no construction. In another study
involving short term and long term work zones on freeways, Rouphail and
others showed that the crash rates during construction increased by 88
percent compared to the "before" period at long-term work zones and the
crash rates for short-term work zones were not affected by the road
work. Garber and Woo found that on average the crash rates at work zones
on multilane highways in Virginia increased about 57 percent; on
two-lane urban highways the increase was about 168 percent when compared
with crash rates prior to the installation of the work zones. In a study
conducted on all type of roads, Pigman and Agent showed that crash rates
during construction exceeded those in the before period at 14 of 19
sites. In another study conducted along rural interstates, Nemeth and
Migletz also showed that crash rates during construction increased
significantly compared to the before period.

In several studies involving work zones along two-lane highways, the use
of a combination of cones, flashing arrows, and flaggers on multilane
highway work zones and a combination of cones, flaggers, or 4 static
signs and flaggers resulted in the fewest crashes whereas the use of
flaggers at urban work zones resulted in the fewest crashes.

**Crash Severity**

Studies concluded that work zone crashes were more severe than other
crashes, involving a high number of worker fatalities. The average work
zone crash was more severe than the average crash in terms of the number
of vehicles involved and average property damage.

**Crash Location**

The location of crashes is an important aspect in analyzing for suitable
countermeasures and devices to be adopted for the type of crash. Several
studies addressed the locations of crashes in work zones. Two studies
found that most crashes occurred in the work area (combining the
longitudinal buffer and activity areas). Nemeth and Migletz found that
39.1 and 16.6 percent of accidents occurred in the longitudinal buffer
area and in the activity area, respectively at single-lane, crossover,
and bi-directional zones (two-lane two-way operation).

From studies conducted related to work zone crashes, it is concluded
that the activity area was the predominant crash location, followed by
the transition area, the advance warning area, the longitudinal buffer
area, and the termination area. The Typical work zone is shown in Figure
11. Figure 12 shows a graphical representation of results obtained based
on crash location on work zones.

Figure 3 shows a pie chart that represents the distribution of work zone
crashes by road type. Although the highest percentage of work zone
crashes occurred on urban interstate highways, it cannot be concluded
that these highways are more susceptible to work zone crashes, as these
crashes were not normalized for traffic volumes or for the number of
work zones on each type of road. The data that would be required for
such an analysis was not reported in the literature.

![](media/image12.wmf){width="5.997916666666667in"
height="2.795138888888889in"}

Figure 11: Location distributions of Work Zone Crashes

![](media/image13.wmf){width="5.84375in" height="2.9791666666666665in"}

Figure 12: Road type distributions for all work zones

In a recent study conducted by Garber and Ming, the results indicate
that the activity area was the predominant location for work zone
crashes regardless of highway type and that rear-end crashes were the
predominant type of crash. The results also indicated that the
proportion of sideswipe same direction crashes in the transition area
was significantly higher than in the advance warning area and that work
zone crashes involved a higher proportion of multi-vehicle crashes and
fatal crashes.

**Crash Type**

The results of several studies indicated that rear end crashes were the
predominant collision type in work zones. Richards and Faulkner found
that rear-end accidents account for 40 percent of accidents reported in
work zones. They attributed this to slowing among preceding vehicles.
Single-vehicle, fixed object accidents were the second highest,
representing over 15 percent of all accidents reported in work zones.
Pigman and Agent found that, as suspected, work zone crashes involving
heavy vehicles were more severe than those in which heavy vehicles were
not involved. Pigman and Agent also found that crashes during darkness
were more severe, whereas Nemeth and Migletz found that crashes during
daylight hours were more severe than those at night or at dawn and dusk
and that single-vehicle crashes were predominant at night. Two studies
concluded that nighttime crashes were especially concentrated in the
transition area.

A summary of major studies conducted on crash characteristics and
coverage of crash characteristics are tabulated in Table 2 and Table 3
respectively.

### Table 2. Major Studies Concerning Crash Characteristics

![](media/image14.wmf)

### Table 3 Coverage of Crash Characteristics in Various Studies

![](media/image15.wmf)

**Technologies to Reduce Crashes in Work Zones**

A1998 report by the Federal Highway Administration, noted that the two
leading causes of work zone crashes are excessive speed and driver
inattention. Further, it noted that there is universal agreement that
the most effective way of controlling speed in the work zone is to have
a staffed police car with flashing lights at the onset of the work zone.
Drivers detect the presence of police either visually or via radar
detectors and reduce their speed to comply with the posted work zone
speed limit. The reduced speeds and reduced variation in speeds result
in fewer accidents or less severe accidents and minimize dangerous
interactions between vehicles and workers and equipment.

Traffic control devices used in work zones should strictly follow the
MUTCD requirements. Shielding the activity area in a work zones can be
done using devices such as Balsi beam, traffic cones, and portable
barriers. Additional protection of work zones can be done using
intrusion alarms, rumble strips, truck mounted attenuators and effective
advance warning signs such as --"Be Prepared to Stop", - "Shoulder work
Ahead", -"Work Zone Approaching" which would draw driver attention.
Warning drivers of queues ahead is another method of preventing crashes
caused by vehicles following too closely. Devices such as queue
detectors combined with changeable message signs could warn drivers well
in advance.

A thorough literature search was conducted using all the available
resources for identifying devices and technologies, which are effective
in catching driver's attention. Among various techniques that are being
employed by various DOTs, intrusion alarms and portable rumble strips
which are the most widely used devices.

[Rumble Strips]{.underline}

In an effort to promote safer conditions in work zones, the Kentucky
Transportation Center, in conjunction with the State of Kentucky and the
Federal Highway Administration (FHWA), sponsored a project to
demonstrate the use of the portable rumble strip at maintenance work
zones across the State. When drivers feel the vibration and hear the
sound caused by the portable rumble strip, they are given a final
reminder that they are about to enter a temporary work area.

Developed by the Strategic Highway Research Program (SHRP), the portable
rumble strip is placed across the road about 100 m (250 ft) in advance
of the work zone. The device causes a vibration in the steering wheel
and a rumble as vehicles pass over it, warning drivers that conditions
on the road will soon become dangerous. The portable rumble strip is
best suited for low-speed roads that carry few heavy trucks. The
portable rumble strip is also easy to use. The device weighs about 34 kg
(75 lb), and one or two workers can deploy it from the back of a pickup
truck.

A number of studies have demonstrated the benefits of shoulder rumble
strips in reducing death and serious injury caused by inattentive
drivers in Run-off-road (ROR) crashes. The methodologies used in these
effectiveness studies and their results vary from state to state, but
all show some measure of crash reduction attributed to the presence of
shoulder rumble strips.

**[Intrusion Alarms]{.underline}**

Drivers sometimes fail to notice the signs, cones, and other warnings
that they are approaching a highway work zone. Intrusion alarm developed
under the SHRP provides safety to workers in the work zone either by
audio or visual means, when a motorist intrudes into the work zone.
State of Vermont is using these alarms to inform the workers well before
the danger. Example of audio intrusion alarm is a flashing strobe light,
which activates as soon as a driver by mistake enters in the danger part
of a work zone. The biggest benefit is that the workers get few seconds
to clear out of danger way.

After testing two models of the work zone intrusion alarm, Vermont
AOT\'s research unit purchased a model that uses an infrared beam sent
from a transmitter unit to a receiver unit that also houses the siren.
When a vehicle breaks this beam, the siren goes off. The research unit
picked this model because it was the fastest and easiest to set up.

## **ALTERNATIVE STRATEGIES AND TECHNIQUES FOR TRAFFIC CONTROL**

**Technologies**

Workers in rural short-term maintenance work zones are placed in a
particularly hazardous position. Short-term and mobile maintenance work
zones are typically located on high-speed roads; with traffic control
installed each day in the morning and removed by dusk. Since these work
zones are in place only for a short time, drivers do not expect to
encounter them. Regulatory speed limits cannot be lowered at the sites,
and it is difficult to get law enforcement agencies to regularly patrol
temporary work zone sites in rural areas. Studies conducted at work
zones evaluated a large number of innovative traffic control devices
that had the potential to improve safety in short-term work zones.
Researchers examined countermeasures that would increase driver
awareness of the upcoming work zone, make workers more visible, or slow
down traffic. Since these work zones were in place only for a short
time, it was also essential that each device be easily set up and
removed.

**[Flashing Lights]{.underline}**

Research sponsored by the Texas Department of Transportation (TxDOT) and
conducted by the Texas Transportation Institute (TTI) has revealed
helpful techniques that improve safety for workers and increase
visibility of work zones for motorists. The researched techniques is
shown in Figure 13. In a general scenario, the indication of a work zone
ahead is given to the drivers by flashing yellow warning signals or a
sign telling to move from one lane to the other. A new method of warning
drivers of approaching work zones is proving to be safer and easier to
understand from greater distances. The approach was developed as a part
of a TTI research project that was sponsored and implemented by TxDOT.
It utilizes a series of synchronized flashing lights attached to the
drums that form a lane closure taper. The flashing lights illuminate in
a sequence from the beginning to the end of the taper. According to
closed-course studies at TTI\'s

> ![](media/image16.png){width="4.124305555555556in"
> height="2.2604166666666665in"}
>
> Figure 13 Texas DOT Flashing Lights

Riverside Campus in College Station and roadway tests in Houston,
drivers responded more positively to the synchronized flashing light
system than to the normal traffic control setup used at construction
sites in Texas. It was also found that as the synchronized flashing
warning light system was activated, there was a one-fourth reduction in
the number of passenger vehicles 1,000 feet before the lane closure
taper.

**[Dancing diamonds (lights)]{.underline}**

In this context, it is also pertinent to discuss here arrow panels
consisting of a matrix of lights. Non-directional arrow panel displays
are designated as caution displays. Before 2001, literature lacked
significant statistical support for any one type of caution display. A
2001 Oregon Department of Transportation (ODOT) study suggested that
the + ACI-dancing diamonds are better than the other caution displays
like flashing box. ODOT also found that local citizens preferred the
dancing diamonds to other caution displays. However, additional research
was needed to confirm these findings. The lights are shown in figure 14.

To evaluate the effectiveness of the dancing diamonds and +ACI- flashing
box+ACI- displays, a field experiment was conducted. The results of this
experiment showed that the dancing diamond was associated with a
statistically significant 3 km/h (2 mph) reduction in mean speeds,
whereas the flashing box display was associated with no statistically
significant reduction in mean speeds, indicating that the dancing
diamonds prompt safety near highway work better than the flashing box.

[Rotating lights / Strobe Lights]{.underline}

This comprehensive research report published by TRB was developed due to
the growing concern of increasing frequency of hazards during moving and
short-term work zone operations. The research was very thorough and
effective in a way that it encompassed different possible formations of
mobile maintenance operations. Eleven categories of short-term and
moving work zones contained corresponding traffic control devices,
vehicle warning light systems and driver

> ![](media/image17.gif){width="4.124305555555556in"
> height="2.3958333333333335in"}
>
> Figure 14 Dancing diamonds (lights)

actions respectively. Though studies supported traffic control devices
(TCD) applications and guideline development, it was also found that
accident reduction was the ultimate measure of device effectiveness.

This research mainly focused on human response to warning lights varied
by the type of light both in closed field and operational tests. It was
found during research that no one light is maximally effective in both
transmitting information and gaining attention. The reason for this was
that rotating and strobe lights, which were effective in getting
driver's attention, were not as useful in providing speed and closure
rate information especially when the service vehicle was stopped.
Conversely flashing lights, which worked really well for giving speed
info, were not effective in providing clear clue of working zone to
drivers from long distances. Therefore several of the lighting
recommendations combine the two types of light in order to ensure
optimum information transmission and conspicuity.

Apart from the findings related to different types of lights
functioning's, cost benefit analysis was developed to aid in making some
of the decisions. Some of the devices like shadow vehicles were found to
be very effective in producing desired results but involved substantial
costs as well. Therefore separate cost-effectiveness criteria were
included as a basis for agency-specific decisions regarding its use.

[Advanced Warning Signs]{.underline}

The Virginia Department of Transportation (VDOT) is continuously
striving to improve the flow of traffic as well as to protect workers
and motorists in work zones. By using an advanced warning sign that is
easily understood by motorists, both motorists and workers benefit. VDOT
and several other state departments of transportation have expressed
interest in modifying the advanced warning signs for work zone
operations. The advanced warning sign is intended to alert drivers and
to prepare drivers to stop (if necessary) prior to reaching work zone
operations. Typical advanced warning signs are shown in figure 15.

> ![](media/image18.jpeg){width="2.2180555555555554in"
> height="1.0416666666666667in"}
>
> ![](media/image19.jpeg){width="2.0409722222222224in"
> height="1.0416666666666667in"}
> ![](media/image20.jpeg){width="2.0409722222222224in"
> height="1.0416666666666667in"}
>
> ![](media/image21.jpeg){width="2.03125in"
> height="1.0416666666666667in"}
>
> Figure 15 Typical Advanced Warning Signs

For example the construction vehicle sign warns drivers that the truck
they are following is a construction vehicle and may leave the lane to
enter an active work area.

Flashing arrow boards warn drivers that the lane they are traveling in
is closing ahead and a lane change is required. The arrow direction will
indicate which lane is open for travel.

Similarly, when only the four corners of the board are flashing, drivers
must use caution, but do not change lanes. This light pattern is also
used when work is on the shoulder of the roadway.

[Variable Message Signs]{.underline}

Highway maintenance projects create difficulties for highway workers and
motorists alike. Project crews work just steps away from passing
traffic, usually separated by only a line of plastic barrels or cones.
Motorists must navigate changing traffic patterns, which can cause
delays and frustration. They also face an increased risk of rear-end
collisions caused by sudden changes in travel speed. Typical variable
message sign is shown in figure 16.

It\'s not that motorists haven\'t been warned to slow down as they
approach the work zone; rather, many motorists fail to heed the warnings
because they find the signs unreliable. They\'ve seen too many \"Slow\"
and \"Work Zone Ahead\" signs that are still in place after the crews
have gone home, or variable message signs whose messages do not reflect
current traffic conditions.

Several manufacturers are working to solve this problem by developing
systems that use variable message signs to display messages based on
real-time measurements of traffic conditions. One such system is
*Adaptir (Automated Data Acquisition and Processing of Traffic
Information in Real-Time)*, a technology developed by the Scientex Corp.
with support from the Federal Highway Administration (FHWA) and the
Maryland State Highway Administration.

The Adaptir system measures traffic speeds using Doppler radar, the same
technology used by police to detect speeders. Traffic speeds are
measured at several points within and upstream of a work zone. The data
are then sent to a central control system, which analyzes the data to
pinpoint patches of traffic congestion and delay and then selects the
appropriate prerecorded message to post on a variable message sign- -or
series of signs\--just upstream of the site. The messages prepare
motorists for actual traffic conditions ahead. For example, if traffic
is extremely slow in the work zone, a variable message sign upstream of
the work zone might warn of a 10-minute delay ahead; a second sign might
then warn drivers to slow to 55 km/h (35 mi/h). If traffic speeds
decrease further, indicating worsening congestion, the system would
automatically change the signs to indicate an even longer delay and
advice of slower speeds ahead. The signs can also be used to suggest
alternate routes or tell drivers to tune in to a highway advisory radio
station. To emphasize the timeliness of the messages, each sign can also
display the time the message was posted. Drivers armed with information
on traffic ahead are better prepared for changing traffic conditions and
thus more likely to have a safe trip. The economic benefits of reducing
delays and improving safety at a work zone can outweigh the cost of the
Adaptir system by a factor of six or more, according to an economic
analysis conducted by Scientex.

**[Speed Display Trailer]{.underline}**

This evaluation utilized a trailer-mounted speed display provided by
TxDOT. The unit, figure 17, features a 24-inch LED display and uses
Ka-band radar to detect oncoming vehicles. The display has a strobe lamp
that flashes when a vehicle is detected traveling over a preset speed
threshold. This feature is intended to simulate the operation of photo
radar, possibly decreasing speeds through the

> ![](media/image22.jpeg){width="3.6868055555555554in"
> height="2.3965277777777776in"}

Figure 16 Variable Message Signs

> ![](media/image23.png){width="3.3722222222222222in"
> height="2.9972222222222222in"}
>
> Figure 17 Speed Display Trailer

threat of automated enforcement. During this evaluation, the speed
threshold for the strobe light was set at 75 mph. The display also has a
130 dB siren that can be activated by vehicles traveling over a preset
speed. This option is intended to warn workers when an extremely
high-speed vehicle is approaching.

This device proved to be effective in short term/mobile operation as the
display could be set up in under 10 minutes. The controls were easy to
operate, and TxDOT crews that have used the device have reported no
maintenance problems.

[New Dynamic Message Systems Technology]{.underline}

The 3M Company produces a "Scotchlite LED-1 Pixel" technology with
fluorescent reflective material and high output InGaAIP light emitting
diodes. The LEDs are embedded in the fluorescent reflective panel for
improved reflectivity. This new technology is used in the 3M Variable
Speed Limit Sign to improve sign visibility and alert drivers. The
technology is shown in figure 18.

[Glowing Safety Lights]{.underline}

The Safe Lites Company produces "Bright Zone Signs". The technology
incorporates small glow lamps which are composed of phosphors that are
ignited by small electrical charges. The lamps can be hardwired into a
vehicles electrical system or to rechargeable Lithium batteries for
vests and wearing apparel. The glowing lamps can be seen from a farther
distance than standard illuminated signs and reflective materials, and
significantly improve the visibility of works at night.

![](media/image24.wmf){width="2.423611111111111in"
height="4.000694444444444in"}

> Figure 18 "Scotchlite LED-1 Pixel" technology with
>
> fluorescent reflective material

**Effectiveness of Police Presence and Enforcement Measures**

The use of police enforcement in work zones is a common practice among
State DOTs especially during short term/mobile operations. Since
inattention and irresponsible behavior by drivers are suspected to
contribute to the frequency of work zone crashes, a program featuring
presence of and enforcement by law officers has been implemented by many
states to alleviate the effect of crashes in work zones. Several studies
found that the use of extra enforcement in work zones is a common
practice in many states and that these practices appear to be
increasing. There are several benefits of increased law enforcement
police presence and activity in work zones indicated in literature,
survey responses and worker interviews. Limited congestion increase has
been reported from these efforts. Enforcement activities in work zones
has proven beneficial in reducing speeds, ensuring compliance with
traffic regulations, and improving safety for workers and motorists.

A study concerning the use of uniformed police officers on federal-aid
highway construction projects was prepared pursuant to Section 1213(c)
of the Transportation Equity Act for the 21st Century (TEA-21). It
concluded that the majority of states use uniformed police officers in
at least some work zones where there are particular traffic safety
concerns. Officers are commonly deployed both day and night and in a
variety of locations within and in advance of actual work activities.
The states' survey responses stated an overwhelming opinion that extra
enforcement has benefits in both lowering speeds and improving safety in
work zones.

The FHWA engineers work closely with state highway engineers and law
enforcement officials to identify appropriate engineering safety
countermeasures for high-risk locations and for new roads.  FHWA also
works with the enforcement community, such as the International
Association of Chiefs of Police (IACP), regarding the effective use of
uniformed police officers on federal-aid highways.  FHWA additionally
works with emergency medical services, police and fire organizations to
ensure that public safety is maintained at high levels and access for
emergency vehicles is possible during work zone operations.        

**[Work Zone Enforcement Technology]{.underline}**

Police enforcement relies on personal presence supplemented with
technology tools such as radars and laser guns. Jones and Lacey (1997)
conducted a study in Iowa to determine the effectiveness of laser-based
speed enforcement programs compared with radar during 1994--1995. Radar
and laser speed measurement devices were used extensively in the cities
of Dubuque and Council Bluffs, respectively. Both cities increased speed
enforcement activities during the study period and raised public
awareness of the risk for being cited for speeding violations. Speed
data were collected once each week at 10 locations in each city before
and after the enforcement program implementation. The study found that
the radar-based speed enforcement program decreased the percentage of
vehicles traveling more than 5mph over the posted speed limit by about
20 percent. This observation may be partially explained by the prior
existence of a higher level of speed compliance in that community. The
researchers concluded that laser-based speed measuring devices should
supplement rather than replace existing radar measuring technology.

**[Remote Speed Enforcement]{.underline}**

Another technology and strategy currently considered in work zones is
real-time remote speed enforcement. A study conducted in several work
zones in Europe conclude that due to high speeds and traffic volumes in
many work zones, stopping drivers for traffic violations may be
dangerous for both motorists and officers. A remote speed enforcement
program uses automated speed enforcement (ASE) system to detect
violators and alert an officer located beyond the work zone of the
violation. ASE can use a variety of technologies (e.g., radar, LIDAR,
elapsed travel measurements, and in-pavement sensors) to detect vehicle
speeds. When a violation is detected, a photograph of the vehicle
license plate is taken and transmitted to officers stationed outside of
the work area. After the violating vehicle has passed through the work
area the motorist can be stopped safely. ASE programs can also mail
tickets to the owner after a vehicle has been identified. In most states
criminal citations cannot be issued using only ASE evidence.

ASE systems have also been employed in the United States. Several
communities have used or are currently using ASE. It is common for
communities using ASE to experience a decline in both speeding
violations and crashes^22^. For example, in Paradise Valley, Arizona,
noted a decrease in crashes from 460 in 1986 to 224 in 1992 after
implementing an ASE program. Similarly, West Valley, Utah, observed a
decline from 2,130 to 1,710 crashes annually after using ASE for two
years. A Texas Transportation Institute study examined whether a remote
enforcement system was technically feasible and whether vehicles could
be correctly identified downstream, and surveyed the attitudes of law
enforcement agencies regarding the system. The study found that a
downstream observer could correctly match about 84 to 88 percent of the
offending vehicles. One problem observed was in the transmission of
photographs to an officer downstream. Speed thresholds may need to be
established to ensure hardware/software processing capabilities are not
overloaded. The law enforcement community expressed concerns with the
legal aspects of the system. Some officers and officials believe that
modifications would need to be made to the system and/or to state codes
to permit enforcement using only photographic evidence.

South Dakota completed a study during 1998 using three deterrents to
reduce speeds in work zones: video/LIDAR, a Highway Patrol car, and a
decoy car. The study found the most effective option was a decoy car
parked on the shoulder. A problem found with the active Highway Patrol
car was that when the officer left in pursuit of a violator, he/she was
absent from his/her position at the beginning of the work zone for 15
minutes or more. The South Dakota DOT is currently collecting data using
an ASE system in work zones. South Dakota DOT is planning to present the
findings at a future legislative session in support of legislation to
permit direct mailing of citations. All violators cannot be detected
with ASE, especially on high speed and high volume roadways, but it is
believed that an ASE system can identify many more violators than a
single police officer.

**Work Zone Law Enforcement Functions**

Police officers can be utilized in work zones in many different
applications, such as:

-   keeping travel lanes free of illegally parked or stalled vehicles on
    detour routes and major traffic arteries by arranging for removal

-   controlling illegal turning movements that may restrict capacity at
    intersections directing traffic in congested situations

-   providing advance warning of heavily congested or stopped traffic in
    advance of a problem area, such as a lane closure

-   assisting in traffic control for special construction events, such
    as bridge beam erection and changes in traffic patterns

-   observing and reporting traffic problems on state highways or detour
    routes to the appropriate engineering staff

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-   enforcing speed and any other restrictions in or near the work zone
    area

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-   aiding in traffic control during the daily signing setup and
    takedown activities

-   preventing intrusions into closed lanes, exits

A study conducted by Virginia DOT surveyed several work zone crews, and
that the officer be stationed in the lane closure 500 to 1,000 feet in
advance of the first work crew. If traffic backs up, then the officer
should be in advance of the backup. Sixty percent of the respondents
reported that the officer was most typically located at the beginning or
in advance of the lane closure, and 50 percent reported the location as
inside the work area, either near the workers or away from the workers.
Only 4 percent of the respondents noted the location as at the end of or
following the work area. There were also comments suggesting that VDOT
or VMS personnel assign the location, that the officer position should
depend on the location of the work zone, and that officers be mobile and
patrol the entire work zone and thus are not located at any one place.

However, the benefits of enforcement appear to have not been intensively
quantified. In addition, procedures for the use of law officers in work
zones are quite inconsistent across the nation, and so is the general
implementation of specific legislation addressing work zone traffic
violations. Variation can also be found in funding levels and sources
for enforcement activities in work zones among the states. Training of
law officers prior to work zone duty is not mandatory, but it would be
better to provide them with adequate training for their work zone duty.

As crashes and deaths continue to rise annually in work zones, it is
imperative that beneficial enforcement programs such as the use of law
officers in work zone be continued, refined, and expanded. Future
studies are needed to supplement the knowledge base and provide guidance
to agencies when considering the use of law enforcement to calm traffic,
ensure compliance with traffic laws, and thus provide for safer work
zones.

**Guidelines for Use of Extra Enforcement**

Studies have been undertaken to establish guidelines for assigning law
enforcement officers to work zones. In 1995, the FHWA developed
guidelines for use of uniformed police officers on federal aid projects
in Massachusetts. The FHWA conducted interviews with Massachusetts
Highway Department personnel from Construction, Traffic, and Design
Divisions. Interviews were also conducted with personnel from the
Massachusetts Turnpike Authority, the Massachusetts State Police, and
the Boston Police Department. Considering information gathered from the
interviews (and after consulting the national MUTCD, the state of
Massachusetts and local training manuals, and current nationwide
practices) the FHWA recommended guidelines to determine when uniformed
police officers or civilian flaggers should be used for traffic control
on federal-aid projects in Massachusetts. It was recommended that
flaggers and uniformed traffic officers should be used only when
standard temporary traffic control measures do not adequately guide
traffic and provide safety for motorists and workers. The guidelines
also state that use of flaggers may be necessary to control traffic on
alternating one-way operations or other situations where supplemental
information must be provided. Flaggers may be replaced with police
officers when high traffic speeds, high traffic volumes, or other
extenuating circumstances occur. The guidelines suggest that a uniformed
traffic officer with a marked patrol car and flashing, lights should be
assigned to nighttime operations. A summary of the guidelines is
provided in Table 3.

### Table 3. Guidelines for Flaggers and Uniformed police

![](media/image25.png){width="6.1625in" height="5.075694444444444in"}

In 2002, NCHRP Report 476 proposed traffic control guidelines for
nighttime maintenance and construction projects. The report states that
for all nighttime work activities, the need for and extent of police
services should be considered. It was concluded that visible police
enforcement is highly desirable in nighttime operations to encourage
driver adherence to traffic regulations and to manage incidents such as
crashes, breakdowns, and major congestion. Criteria suggested police
services might be advisable for nighttime operations as follows:

-   construction activities closely adjacent to traffic without positive
    protection

-   restrictions to traffic flow based on work zone features (e.g., no
    shoulder, reduced shoulder width, reduced lane width, or reduced
    number of travel lanes)

-   locations where incidents are expected to produce substantial
    congestion and delays

-   special operations that require traffic control or shifts of the
    traffic pattern

-   locations where traffic conditions and crash history indicate that
    substantial problems may be encountered during construction

-   projects with heightened public concern regarding the impacts of the
    traffic control plan

Other factors that should be considered include traffic speed and volume
through the construction site. Engineers may also wish to refer to these
criteria when deciding whether or not to use extra enforcement during
daytime activities.

**Work Zone Enforcement Legislation**

The Texas Transportation Institute (TTI) conducted a survey regarding
work zone legislation in 1997 and provided updated related information
on the National Work Zone Safety Information Clearinghouse (NWZSIC)
website in 2002. The survey found that 47 states have implemented higher
fines for traffic violations in work zones. Enhanced enforcement
penalties in most states are applicable to all types of work zones:
construction, maintenance, and utility. However, some states limit
application to construction areas only.

Of the 47 states with increased fines in work zones, 32 apply the higher
penalties only to speed violations, while increased fines can be issued
for all traffic violations in 11 of the responding states. Four states
describe specific traffic violations where higher fines can be applied,
such as reckless driving, driving under the influence, improper
passing/overtaking, and following too closely.

Some states actively enforce more than just moving violations in work
zones. Michigan, Montana, Oregon, and Washington have enacted
legislation allowing a driver to be charged with reckless endangerment
of highway workers in a work zone. The state of Oregon also permits
drivers to be cited for refusing to obey a flagger. Similarly, Utah
allows tickets to be issued for failure to obey a peace officer or other
traffic controllers in construction or maintenance zones.

Increased fine amounts vary from state to state; most commonly, standard
fine rates are doubled for work zone violations. Midwestern states that
apply double fines include Iowa, Kansas, Nebraska, and South Dakota.
Fifteen states with increased fines in work zones use fixed amounts for
violations. In Missouri, for example, moving violations in work zones
are assessed the standard fine amount plus 35 dollars.

The TTI survey found that about one-half of responding states with
higher work zone fines require appropriate signing to notify motorists
of this fact. Furthermore, approximately half of the states apply
increased fines only if workers are present in the work zone. In
addition to requiring workers to be present for higher fine application,
Illinois has a policy and Tennessee a code provision requiring flashing
lights to indicate workers are present.

South Dakota is the only state that authorizes agents or employees of
the State department of transportation to issue citations within work
zones for speeding and other violations. Despite the commonality of
increased penalties for violations among the states, analyses of fatal
crashes in work zones between 1984 and 1995 indicated no consistently
measurable effect on fatal work zone crash frequency due to higher
fines. According to NWZSIC, six states have adopted legislation allowing
a speed limit reduction within a work zone without a traffic engineering
investigation.

**Education and Awareness Programs**

Engineers and planners have the responsibility to make sure the work
zone is designed and operating properly with safety in mind.  Drivers
and pedestrians have the responsibility to always be alert and obey the
traffic laws.  Passengers should always buckle up and act responsibly.
The police and the courts have the responsibility to make sure that the
traffic and work zone laws are enforced.  Public safety agencies have
the responsibility of responding to and securing crash locations and
enforcing traffic laws. Local communities and county and state
governments need to allocate funding for safe roads and increase public
awareness about work zone safety.  Everyone should take some
responsibility for work zone safety.

Several public awareness and technical training is conducted through
wide range of activities such as: training courses for federal, state
and local highway engineers, worker and drivers; conferences, CDs,
brochures for the general public and work zone employees; clearinghouse
website; bilingual safety public outreach materials; national work zone
awareness week where national, state and local public activities seeks
to raise public consciousness about the need for driving safely in work
zones.

The National Work Zone Safety Information Clearinghouse started in 1998
by FHWA and the American Road and Transportation Builders Association
(ARTBA), provides excellent educational resource reaches the public and
the highway community. 

Young drivers are prone to create more crashes. In order to educate
young drivers, FHWA has produced Moving Safely across America, an
interactive CD that is being distributed to 15000 driver education
teachers. FHWA is also producing innovative tolls and materials for
increasing work zone safety awareness and safe driving to teen drivers.

Good work zone practices of state transportation agencies all over
United States, strictly following MUTCD requirements is compiled into a
Best Practices Guidebook (available at
<http://www.ops.fhwa.dot.gov/wz/workzone.htm> or on a CD). In the Fall
of 2003, FHWA published a Traffic Control Handbook for Mobile Operation
at Night that describes detailed guidance for night time construction,
maintenance and utility operation.

## FHWA maintains good database on recent work zone related research, developments, safety statistics, and technology transfer. These resources are updated regularly and made available to researchers and engineers.

## **[Worker Education Programs]{.underline}**

## Many state agencies provide periodic worker education programs to inform and encourage safe work practices when workers are exposed to traffic and entering the work zone. These programs include the proper personal attire, use of safety equipment, safety set-up rules and procedures, and conduct. Periodic programs are held monthly, quarterly and semi-annually in a central location or in regional headquarters. Courses are given by agency safety personal and in some instances by professional teaching staff to discuss and inform the worker of new procedures as well as standard procedures. In addition to the worker education programs, agencies provide safety inspectors to regularly check agency work zone safety procedures and correct deficiencies as they occur. Although it may be difficult to measure the effectiveness of such programs, these programs intuitively suggest a concern for safety on the part of the management and an awareness of safety on the part of the workers. 

## **[Program Implementation]{.underline}**

Many state DOT sponsors work zone-oriented public information programs
to reduce the number of crashes in work zones. In Iowa, the current
program, \"Expect the Unexpected in the Work Zone", is a by-product of
the popular television series, \"The Twilight Zone". The major
components of the program are: an educational curriculum for grades K-12
(this includes a six-minute video tape and a classroom instructor\'s
guide that includes student activities to increase awareness of the need
for safe driving in work zones), public service announcements and paid
advertising for television, radio, newspapers and magazines to get
information about safe driving in work zones directly to the motoring
public, brochures, stickers, and posters. Several DOTs' and FHWA
propagate tips for driving safely in work zones.

Like drivers, workers need to be guided by educating them to make sure
the existence of a work zone with all its parameters in place, i.e. all
the devices should be in right place and working properly. Secondly if
it's the night operation then all devices should be reflectorized or
illuminated. It should be ensured that all the maintenance vehicles
should be within the vicinity of a work zone. In addition, workers with
specific traffic control responsibilities should be trained in traffic
control techniques, device usage and placement. Don't assign untrained
workers the responsibility for setting up and maintaining the system.
Workers should be given true information and training and all devices
and signs should be removed that are not in use, meaning that there
should be minimum hindrance to the free flow of normal traffic. Drivers
should not be made to think, respond, brake rapidly by awkward placement
of devices and usage of signs. Another important thing to note is that
safety features may provide adequate warning for a vigilant driver, but
may be inadequate for an inattentive driver. It means that drivers
should be guided in a clear and obvious manner throughout the work zone.

[CB Wizard Alert System and Program]{.underline}

The device is a portable radio that broadcasts real-time work zone
information and safety tips to citizens through radio channels. This
device is especially good for truckers by letting them know about the
traffic patterns through latest updated news. It is designed to give
drivers monitoring the CB radio advanced warning of upcoming delays at
construction sites or incidents.  The advanced warning will allow
drivers the opportunity to moderate their speed and become observant of
the need to slow, stop, or maneuver before they reach the work zone or
encounter queues of halted vehicles.  Since truck operators most
commonly monitor CB radios, it was assumed that the CB Wizard would have
the most impact on truck drivers.  With Certificate of Approval issued
in January 1998, Penn DOT is using the device.^41^

### Work Zone Evaluation Methods

There has been a dedicated effort over the past five years to minimize
impacts to the public as they travel through work zones. While national
data on the cost of work zone delays is not readily available, daily
road-user delay costs on many urban freeway reconstruction projects have
been calculated to be over \$50,000 per day. Because of the significant
impacts to the public in terms of delay and user costs, the Federal
Highway Administration (FHWA) established the Strategic Work-Zone
Analysis Tools (SWAT) program ^29,\ 32^. It addresses work-zone factors
and stresses the importance of accounting for work-zone influences when
making transportation improvement decisions. Three tools are being
developed as part of the SWAT program:

a.  "Expert System" software program;

b.  "Quick Zone" software program

c.  A Detailed simulation model.

*a. Expert System*

With the Expert System, a user would enter data on the characteristics
of the work zone, such as the type of highway improvement or repair work
being done and the duration of the work. The program would then provide
a list of possible mitigation strategies for reducing work zone delays
and costs. The software is still being developed by FHWA and its
expected release date is 2004. More information can be found on the FHWA
Turner-Fairbank Research Center web site at
<http://www.tfhrc.gov/its/swat.htm>.

*b. Quick Zone*

A prototype version of Quick-Zone, new work zone delay estimation
software developed by FHWA in cooperation with Mitretek Systems, is now
available on the web for use and assessment. A user need only have
Microsoft Excel 97 or higher running on a Windows-based PC to use the
Quick-Zone application. The software allows the user to compare the
traffic impacts for work zone mitigation strategies and estimate the
costs associated with these impacts. The costs can be estimated for both
an average day of work and for the entire life cycle of construction.
Version 0.99 of Quick-Zone was released in April 2001.

Specifically, the program provides the following functions:

1.  Quantification of corridor delay resulting from capacity decreases
    in work zones.

2.  Identification of delay impacts of alternative project phasing
    plans.

3.  Supporting tradeoff analyses between construction costs and delay
    costs.

4.  Examination of impacts of construction staging, by:

-   location along mainline;

-   time-of-day (peak vs. off-peak); and

-   season (summer vs. winter).

5.  Assessment of travel demand measures and other delay mitigation
    strategies.

6.  Allowing the establishment of work completion incentives.

The software is available for download at FHWA's Turner-Fairbank
Research Center website at: <http://www.tfhrc.gov/its/quickzon.htm>.

*c. Simulation Model*

FHWA's simulation model, planned for release in 2004, is designed to be
used in conjunction with Quick Zone to more precisely estimate the
impacts of specific work zone strategies and the effectiveness of
mitigation techniques. More information about the model can be found at
the Turner-Fairbank Research Center website:
<http://www.tfhrc.gov/pubrds/nov00/strategic.htm>.

Using a software tool like Quick-Zone, work zone traffic impact analysis
could be performed, by selecting appropriate traffic control
recommendations for the safe and efficient movement of traffic through
construction work zones. The Expert System and Simulation Model, planned
for release in 2004, would help in better estimation of work zone
impacts, costs, and delays.

**CONCLUSIONS**

This report documents and summarizes the study "Identification of
Traffic Control Devices for Mobile and Short Duration Work Operations,"
for the New Jersey Department of Transportation. The study was conducted
in three tasks: 1. Literature Search, 2. Evaluation Criteria and
Analysis, and 3. Identify Guidelines to Eliminate Driver
Inattentiveness, and Design Alternative Strategies and Techniques for
Traffic Control. The study was conducted by two groups: the Region 2,
University Transportation Research Center, City College of New York

and the Institute for Transportation Research and Education, North
Carolina State University. Working papers were completed for each of
those tasks.

The objective of this research project is to study mobile and short
duration work zone safety with particular attention to the
identification of work zone safety devices, information systems for the
reduction of safety and congestion, and implementation of innovative
techniques to reduce delays and crashes due to work zones. The specific
objectives are to:

-   Identify state-of-the art work zone safety technologies to improve
    worker safety in mobile work zone and short term maintenance
    operations,

-   Identify information systems for work zone traffic control to reduce
    delays and crashes,

-   Identify "best practices" for the use of law enforcement to improve
    work zone safety,

-   Identify key issues to be considered from public outreach and
    information systems.

-   The identified work zone safety items will provide improvements for
    maximum protection of the motoring public, protection of exposed
    workers in the work zone and of workers in the set up of the work
    zone, and will meet the current standards established by internal
    policies of the NJDOT.

The literature search focused on safety technologies for mobile and
short duration work zone safety technologies from Transportation
Research Board and National Cooperative Research Program publications,
FHWA, State DOT and other agency publications which include web sites of
most national safety organizations. The search identified nine devices
which are used by State agencies or have the potential for use in mobile
and short duration work zones. The devices are:

-   Fluorescent/Bright Signs

-   Reflectorized/Bright Suits and Vests

-   Drone Radar and Speed Indicator/Displays

-   Remotely Operated Autoflagger

-   Truck Mounted Attenuators and Message Boards

-   CB Wizard Alert System

-   Rumble Strips

-   Intrusion Alarm

-   Lane Merger System

The literature from most sources indicates that State agencies use the
MUTCD work zone standards and the caravan approach to mobile and short
duration work zone safety situations.

Texas Transportation Institute survey results indicate the most
significant hazards for all responding agencies were high speed traffic,
and inattentive motorists which resulted in rear end crashes of safety
vehicles and errant vehicles entering the shadow vehicle convey or the
work area. Some state agencies approach the solution to these issues by
incorporating advance warning devices in addition to the standard MUTCD
safety. Such devices and solutions are:

-   brighter or fluorescent signs on shadow vehicles,

-   trail vehicles with speed display boards below the arrow panel,

-   the use of better or additional lighting on shadow vehicles, such as
    solid light bars, blue lights, or light emitting diode(LED) lights,

-   dynamic message boards in advance of the work area, and

-   police to enforce traffic laws.

All of these devices provide the motorist with the optimum warning to
reduce or eliminate crashes and improve worker safety.

The Strategic Highway Research Program researched five devices that have
the potential for increased work efficiency, and improved worker safety
by eliminating direct worker exposure to traffic and mitigating errand
vehicles. The five devices which are discussed the report are:

-   Cone Shooter

-   Automated Pavement Crack Sealers

-   Automated Debris Removal Vehicle

-   Balsi Beam

-   Robotic Highway Safety Markers.

The Balsi Beam has the greatest potential for protecting exposed workers
in short duration work operations. The beam provides a positive
protection from errand vehicles and is crash worthy as tested by NCHRP
testing. Unlike portable concrete median barrier which is time consuming
and labor/equipment intensive to set up, and requires a 42 inch clear
zone between the barrier and the worker, the Balsi Beam can be set up in
less than 10 minutes and requires no clear zone between the beam and
workers. The California Department of Transportation is presently
implementing the barrier for specialized concrete construction and
bridge repair operations on high speed interstate highways. The beam can
be used in maintenance operations wherever workers are exposed to
traffic in a limited area for several hours. No workers have been killed
or injured while working behind the beam.

The FHWA recommends the presence of uniformed police officers on
Federal-aid highway work zones. It further recommends the use of
automated enforcement and intrusions alarms as well as uniformed police
officers to improve traffic safety at highway work zones. The literature
indicates that most State DOT s have programs and policy regarding these
of uniformed police officers at highway work zones.

Motorist Information, Education and Outreach Systems are important tools
for State DOTs. Most DOTs and the FHWA have specific programs to inform
the public and train workers.

The researchers conducted five field observations of mobile and short
duration work operations to analysis and compare current maintenance
work zone operations with the MUTCD and other agencies, as well as
interviews with work zone safety personnel. The safety for mobile
operations of pothole patching, sweeping, spraying and mobile patching
was in accordance with MUTCD requirements. Workers requested improved
devices such as strobe lights and improved reflective materials for
signs to get driver's attention.

The researchers met with California Department of Transportation
engineers to observe the operation of the Balsi Beam and talk to
Caltrans maintenance workers. The Caltrans is implementing the second
generation prototype beam with a bridge and concrete repair crew on
Route I-80 between Marysville and Reno, NV.

Caltrans uses the beam for medina barrier repairs, bridge deck patching
and repairs, slab replacement and joint repairs, installation of bridge
sealers and guiderail and parapet repairs.  The beam is used in
conjunction with other safety equipment - -  TMAs, trucks, signs and
safety set up .   The bridge maintenance crew and foreman were very
enthusiastic about using the beam.  The crew is able to use air
compressors, bobcats and other equipment in the work area of the beam. 
Suggestions have been made to incorporate some of the equipment on the
beam-tractor to make the beam a multi-functional piece of equipment. \
\
Essentially, Caltrans, Division of Equipment, designed the beam with
some assistance from TTI and funding from the FHWA.  Caltrans fabricates
and builds their own trucks and large equipment for maintenance, so they
have extensive equipment design and fabricating experience.  Caltrans
and the FHWA would like to implement the beam in the east coast DOTs.   
At this time, Caltrans does not have the resources to demonstrate the
beam throughout the country, and would like other State DOTs to be
involved in implementation.  The researchers believe this is an
opportunity for NJDOT to improve worker safety, be a showcase and assist
the FHWA for the implementation of the beam in the eastern states. 

The researchers presented the information on the Balsi Beam and a
PowerPoint presentation to Region South and Region North Maintenance
workers and engineers. Both regions were interested in the potential for
the beam to protect workers. However, Region North has the best
application for the beam on bridge and concrete repair projects along
Route I-80 in Northern New Jersey.

**RECOMMENDATIONS**

The NJDOT should fabricate and implement the Balsi Beam with the
assistance of Caltrans and the FHWA on selected short duration work
zones.

The NJDOT should implement "Bright Zone Signs to improve work safety and
visibility of workers in work zones.

The researchers propose to develop a work plan to prepare a licensing
agreement with Caltrans, prepare plans and specifications for bidding,
investigate bidding and fabrication schemes such as fabrication at a
facility in California, inspection and engineering expertise during
fabrication, delivery of the beam, operation training and implementation
studies with NJDOT engineers.