Evaluation of the School Street

Four-Quadrant Gate/In-Cab

Signaling Grade Crossing System

Safety of Highway Railroad Grade Crossings

U.S. Department

of Transportation

Federal Railroad

Administration

Office of Research

and Development

Washington, DC 20590

DOT/FRA/ORD-07/09 Final Report

March 2007

This document is available to the

public through the National Technical

Information Service, Springfield, VA 22161.

This document is also available on the FRA

Web site at www.fra.dot.gov.

D7572.EvalFourQuadGate.qxd:Layout 1 5/9/07 12:45 PM Page 2
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1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 

March 2007 

3. REPORT TYPE AND DATES COVERED 

Final Report 

August 1997-March 2002 

4. TITLE AND SUBTITLE

Evaluation of the School Street Four-Quadrant Gate/In-Cab Signaling Grade Crossing System 

5. FUNDING NUMBERS 

RR297/R2036 

6. AUTHOR(S) 

Adrian D. Hellman, Anya A. Carroll, and Debra M. Chappell 

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 

U.S. Department of Transportation 

Research and Innovative Technology Administration 

John A. Volpe National Transportation Systems Center 

Cambridge, MA 02142 

8. PERFORMING ORGANIZATION REPORT 

 NUMBER 

DOT-VNTSC-FRA-03-04 

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 

U.S. Department of Transportation 

Federal Railroad Administration 

1120 Vermont Ave., NW 

Washington, DC 20590 

10. SPONSORING/MONITORING AGENCY 

 REPORT NUMBER 

DOT/FRA/ORD-07/09 

11. SUPPLEMENTARY NOTES 

12a. DISTRIBUTION/AVAILABILITY STATEMENT 

This document is available to the public through the National Technical Information Service, 

Springfield, VA 22161. This document is also available on the FRA Web site at 

www.fra.dot.gov. 

12b. DISTRIBUTION CODE 

13. ABSTRACT (Maximum 200 words)

Under sponsorship from the U.S. Department of Transportation Federal Railroad Administration, Office of Research and Development, the 

John A. Volpe National Transportation Systems Center performed an evaluation of the four-quadrant gate/obstruction detection system at the 

School Street crossing in Groton, CT. The primary objectives of this evaluation were to assess the safety benefits and to document the 

operational performance provided by this non-standard technology. Highway-railroad grade crossing risk mitigation research in the United 

States has historically focused on the safety benefits of active warning devices, such as flashing lights, bells, and dual crossing gates. In 

addition, clear agreement has predominated within the research community that grade separation or closure provides the highest level of risk 

treatment. As the economic and societal costs of these treatments have increased, however, research has been increasingly concentrated on 

technologies that provide many of the same benefits without the obtrusiveness of grade separation or closure. 

15. NUMBER OF PAGES 

48 

14. SUBJECT TERMS 

Four-quadrant gates, highway-railroad grade crossings, high-speed rail, railroad, 

train operations, signaling/control technologies 16. PRICE CODE 

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Unclassified 

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LENGTH (APPROXIMATE) LENGTH (APPROXIMATE) 

1 inch (in) = 2.5 centimeters (cm) 1 millimeter (mm) = 0.04 inch (in) 

1 foot (ft) = 30 centimeters (cm) 1 centimeter (cm) = 0.4 inch (in) 

1 yard (yd) = 0.9 meter (m) 1 meter (m) = 3.3 feet (ft) 

1 mile (mi) = 1.6 kilometers (km) 1 meter (m) = 1.1 yards (yd) 

1 kilometer (km) = 0.6 mile (mi)

AREA (APPROXIMATE) AREA (APPROXIMATE) 

1 square inch (sq in, in2) = 6.5 square centimeters (cm2) 1 square centimeter (cm2) = 0.16 square inch (sq in, in2) 

1 square foot (sq ft, ft2) = 0.09 square meter (m2) 1 square meter (m2) = 1.2 square yards (sq yd, yd2) 

1 square yard (sq yd, yd2) = 0.8 square meter (m2) 1 square kilometer (km2) = 0.4 square mile (sq mi, mi2) 

1 square mile (sq mi, mi2) = 2.6 square kilometers (km2) 10,000 square meters (m2) = 1 hectare (ha) = 2.5 acres 

1 acre = 0.4 hectare (he) = 4,000 square meters (m2) 

MASS - WEIGHT (APPROXIMATE) MASS - WEIGHT (APPROXIMATE) 

1 ounce (oz) = 28 grams (gm) 1 gram (gm) = 0.036 ounce (oz) 

1 pound (lb) = 0.45 kilogram (kg) 1 kilogram (kg) = 2.2 pounds (lb) 

1 short ton = 2,000 pounds (lb) = 0.9 tonne (t) 1 tonne (t) =

=

1,000 kilograms (kg) 

1.1 short tons

VOLUME (APPROXIMATE) VOLUME (APPROXIMATE) 

1 teaspoon (tsp) = 5 milliliters (ml) 1 milliliter (ml) = 0.03 fluid ounce (fl oz) 

1 tablespoon (tbsp) = 15 milliliters (ml) 1 liter (l) = 2.1 pints (pt) 

1 fluid ounce (fl oz) = 30 milliliters (ml) 1 liter (l) = 1.06 quarts (qt) 

1 cup (c) = 0.24 liter (l) 1 liter (l) = 0.26 gallon (gal) 

1 pint (pt) = 0.47 liter (l) 

 1 quart (qt) = 0.96 liter (l) 

1 gallon (gal) = 3.8 liters (l) 

1 cubic foot (cu ft, ft3) = 0.03 cubic meter (m3) 1 cubic meter (m3) = 36 cubic feet (cu ft, ft3) 

1 cubic yard (cu yd, yd3) = 0.76 cubic meter (m3) 1 cubic meter (m3) = 1.3 cubic yards (cu yd, yd3)

TEMPERATURE (EXACT) TEMPERATURE (EXACT) 

[(x-32)(5/9)] °F = y °C [(9/5) y + 32] °C = x °F

QUICK INCH - CENTIMETER LENGTH CONVERSION

0 1 2 34

Inches

Centimeters 01 3 26 1 4 5 7 1 1098 1 12

5

3

QUICK FAHRENHEIT - CELSIUS TEMPERATURE CONVERSION

 -40° -22° -4° 14° 32° 50° 68° 86° 104° 122° 140° 158° 176° 194° 212°

 

°F

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For more exact and or other conversion factors, see NIST Miscellaneous Publication 286, Units of Weights and 

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ii 
Acknowledgments 

The authors of this report would like to acknowledge the Federal Railroad Administration (FRA) 

sponsors, Claire Orth and James Smailes, Office of Research and Development, and Peter 

Montague, Office of Passenger Programs, for providing technical guidance. The authors would 

also like to acknowledge Anne Donnelly and Ashish Aggarwal, formerly of the Volpe National 

Transportation Systems Center; Michael Lee, formerly of EG&G Technical Services; Marsha 

Haines of EG&G Technical Services; and Bob Marville of CASE, LLC. Additional School 

Street project contributing members were Michael Saunders, FRA Northeast Corridor Program 

Manager, FRA; Steve Szgedy, Connecticut Department of Transportation; Bill Watson and Bob 

Mays, Amtrak; and Lee Vincent and Greg Hanover, Town of Groton, Connecticut. 

iii 

Table of Contents 

List of Figures................................................................................................................................ vi 

List of Tables................................................................................................................................. vi 

Executive Summary........................................................................................................................ 1 

1. Introduction............................................................................................................................ 3 

1.1 Dual-Gate versus Four-Quadrant Gate Crossings................................................... 4 

1.2 High-Speed Rail and Grade Crossings ................................................................... 4 

2. Literature Review................................................................................................................... 7 

2.1 Previous Four-Quadrant Gate Studies .................................................................... 7 

2.2 Four-Quadrant Grade Crossing Modeling .............................................................. 8 

2.3 Motor Vehicle Violations ....................................................................................... 9 

2.4 Effectiveness of Four-Quadrant Gates.................................................................. 10 

3. Four-Quadrant Gate with Obstruction Detection Technical Description ............................ 11 

3.1 General Description .............................................................................................. 12 

3.2 Operational States................................................................................................. 13 

4. School Street Evaluation Plan.............................................................................................. 15 

4.1 Evaluation Categories........................................................................................... 15 

4.2 Observational Setting............................................................................................ 15 

4.3 Motor Vehicle Violation Data Collection and Reduction..................................... 18 

4.4 Operational Performance ...................................................................................... 18 

4.5 Locomotive Engineer Acceptance ........................................................................ 18 

4.6 System Deployment Cost...................................................................................... 19 

5. Results and Discussion ........................................................................................................ 21 

5.1 Before and After Comparison............................................................................... 21 

5.2 Warning Time Analysis........................................................................................ 26 

5.3 Operational Performance ...................................................................................... 27 

5.4 Locomotive Engineer Survey ............................................................................... 28 

5.5 System Deployment Cost...................................................................................... 28 

6. Recommendations and Lessons Learned............................................................................. 31 

6.1 Benefit Analysis to Support Effectiveness Values of Four-Quadrant Gates........ 31 

6.2

......................................................................................... 31 

Comparison of Four-Quadrant Gate Systems with and without Obstruction 

Detection Functionality

6.3 Data Collection Conditions................................................................................... 32 

6.4 Develop Standard Format for Tracking How Grant Money Is Allocated ............ 32 

7. Conclusions.......................................................................................................................... 35 

References..................................................................................................................................... 37 

Appendix....................................................................................................................................... 41 

Acronyms...................................................................................................................................... 47 

v 
vi 

List of Figures 

Figure 1. Functional Diagram of the Four-Quadrant Gate/ODS ................................................. 12 

Figure 2. Layout of the School Street Four-Quadrant Gate and Video Acquisition Systems..... 17 

Figure 3. Distribution of Gate Warning Times for Four-Quadrant Gate Crossing System......... 26 

List of Tables 

Table 1. High-Speed Rail Grade Crossing Treatments.................................................................. 6 

Table 2. Vehicle Violations at the Four-Quadrant Gate System as Compared to the Dual-Gate 

System............................................................................................................................ 22 

Table 3. Vehicle Violations at the Four-Quadrant Gate System as Compared to the Dual-Gate 

System, with Motor Vehicle(s) and Train Present......................................................... 22 

Table 4. Four-Quadrant Gate Seasonal Activity.......................................................................... 23 

Table 5. Four-Quadrant Gate Seasonal Type I Violation Rates .................................................. 24 

Table 6. Dual-Gate Seasonal Type I and Type II Violation Rates.............................................. 24 

Table 7. Four-Quadrant Gate Hourly Type I Rates ..................................................................... 25 

Table 8. Four-Quadrant Gate Type I Violation Events and Vehicle Violations as a Function of 

Train Type...................................................................................................................... 25 

Table 9. Expenditures for ConnDOT/FRA Grant........................................................................ 29 

Table 10. Total Project Expenditures............................................................................................ 29 
Executive Summary 

Under sponsorship from the U.S. Department of Transportation Federal Railroad Administration 

(FRA), Office of Research and Development, the John A. Volpe National Transportation 

Systems Center performed an evaluation of the four-quadrant gate/obstruction detection system 

at the School Street highway-rail grade crossing in Groton, CT. The primary objectives of this 

evaluation were to assess the safety benefits and to document the operational performance 

provided by this non-standard technology. 

Highway-railroad grade crossing risk mitigation research in the United States has historically 

focused on the safety benefits of active warning devices, such as flashing lights, bells, and dual 

crossing gates. In addition, clear agreement has predominated within the research community 

that grade separation or closure provides the highest level of risk treatment. As the economic 

and societal costs of these treatments have increased, however, research has been increasingly 

concentrated on technologies that provide many of the same benefits without the obtrusiveness 

of grade separation or closure. 

Two such technologies, four-quadrant gates and obstruction detection, were demonstrated at the 

School Street grade crossing along Amtrak’s Northeast High-Speed Rail Corridor in Groton, CT. 

The purpose of this demonstration was to show that these technologies, when integrated with incab signaling, yield a high level of safety to motor vehicle users of the system without negatively 

impacting rail operations. Initial indications of the performance of this type of grade crossing 

safety enhancement system are that it will be a valuable treatment option for high-speed rail 

corridors throughout the United States where in-cab signaling or an equivalent type of train 

control system is used. 

1 

1. Introduction 

High-speed rail travel can provide a means for transporting large numbers of people while 

increasing the safety of the overall transportation system. When a rail line is converted from 

conventional to high speed, various infrastructure improvements are required to maintain the 

level of safety. A case in point is the upgrade of Amtrak’s Northeast Corridor (NEC) territory 

between New York City and Boston. In the 1960s, the need to create a high-speed rail system 

corridor between Washington, DC, and Boston was identified and investigated. The High-Speed 

Ground Transportation Act of 1965 responded to increased demand on rail service along the 

NEC by initiating a program of high-speed rail demonstrations. Over the last decade, legislation 

was enacted to coordinate efforts to increase the efficiency of Amtrak service on the NEC 

without impacting safety. In 1994, the Northeast Corridor Transportation Plan (NECTP) was 

published as a Report to Congress. NECTP was a comprehensive plan specifying the 

infrastructure and operational improvements necessary to implement a high-speed rail service 

between Boston and New York City. The infrastructure improvements included 

(1) electrification of the rail line between New Haven and Boston; (2) elimination of grade 

crossing hazards; (3) elimination of speed restrictions; (4) purchase of high-speed trainsets; and 

(5) installation of a high-speed signaling system. 

The Grade Crossing Elimination Plan was included as an appendix to the NECTP. FRA, in 

coordination with the State Departments of Transportation (DOTs) and the respective local 

officials in Connecticut, Rhode Island, and Massachusetts, developed this document, mandated 

by the Amtrak Authorization and Development Act of 1992. The result of this work was a 

master plan for the closure, separation, or alternative treatment of the 15 remaining grade 

crossings on the NEC between New Haven and Boston (FRA, 1994). Under this plan, 12 

Connecticut highway-rail crossings were slated for grade separation or closure. Several of the 

communities that would be affected by the proposed grade separation program, however, deemed 

that the grade separation or closure would be excessively intrusive (FRA, 1994). 

As documented in the NECTP, FRA, Amtrak, and the Connecticut DOT (ConnDOT) conducted 

feasibility studies for the highway-rail crossing located at School Street in Groton. All three 

studies concluded that grade separation, at an estimated cost of $4 million, was the only feasible 

solution. This conclusion was based on the density of rail traffic at the crossing and the fact that 

the crossing was the only entrance to the Willow Point neighborhood of Groton. Each of the 

recommendations, however, met with opposition from the local community over aesthetic and 

environmental concerns. The authors of the NECTP presented a potential alternative solution: 

the demonstration of an enhanced grade crossing system employing four-quadrant gates with 

obstruction detection, hereon referred to as the four-quadrant gate system. The key facets of this 

technology were the four-quadrant gates, detection of motor vehicles and other metal objects 

stalled on the highway-rail crossing, and the integration of the obstruction detection system 

(ODS) with the Amtrak nine-aspect cab signal system. The authors also acknowledged that the 

ODS component could increase the total crossing warning time from the minimum Connecticut 

State requirement of 30 seconds to as much as 150 seconds. The current law in the State of 

Connecticut mandates a minimum warning time of 30 seconds. This increase was necessary 

because of the time required for a locomotive engineer to execute safe braking in response to a 

reduction in the cab signaling system aspect (FRA, 1994). 

3 
1.1 Dual-Gate versus Four-Quadrant Gate Crossings 

Dual-gate grade crossings reduce the risk level over passive crossings and crossings 

incorporating flashing lights. The gate warning time is one variable that affects the risk level of 

motor vehicle driver behavior. For a conventional grade crossing, track circuits installed at fixed 

distances in both directions from the crossing are used to activate the warning devices. This type 

of crossing is known as a fixed distance activation crossing. The relative positions of these track 

circuits with respect to the grade crossing are calculated to provide 20-30 seconds of warning 

time for the maximum civil speed at that location. For example, a crossing with a maximum 

civil speed of 70 mph (113 km/h) will provide a 30-second warning for a passenger train 

traveling at that velocity. However, the warning time for a freight train traveling at a speed of 35 

mph (56 km/h) will be 1 minute. The lack of constant warning time devices at many crossings in 

the United States can pose a safety concern because motorists may not be accustomed to the 

variations. For dual-gate crossings that are not equipped with constant time warning devices, 

such as the pre-existing system at School Street, the concern is that motorists may become 

impatient and drive around the gates. The risk associated with this behavior is magnified for a 

rail corridor that experiences a mix of high-speed and conventional intercity, commuter, and 

freight rail service, such as the NEC in Connecticut. 

One common grade crossing concern is the potential for motor vehicles to become disabled or 

stranded as a result of traffic congestion. The latter scenario often occurs when motorists realize 

the gates are descending and attempt to traverse a crossing before the gates are fully deployed. 

Each year, this scenario results in numerous collisions between trains and motor vehicles. Many 

of these collisions are potentially preventable by ODSs that are integrated with wayside and/or 

in-cab signaling systems. 

Although four-quadrant gate crossings are not a substitute for grade separation in high-speed rail 

corridors, they are designed to mitigate the motor vehicle driver violations associated with dualgate systems. By design, four-quadrant gate systems provide a visual blocking of a crossing and 

tend to prevent motor vehicles from driving around the deployed gates. These crossings may be 

envisioned as the conventional dual-gate system augmented by exit gates. The exit gates prevent 

automobiles from traversing the crossing against the direction of vehicle traffic flow. In the 

event of either a system failure or a vehicle becoming trapped within the crossing, the exit gates 

will raise to the up position, and the entrance gates will deploy to the down position. The 

addition of the ODS provides the two-fold capability of alerting approaching trains equipped 

with in-cab signaling devices to trapped vehicles and releasing the exit gates so that trapped 

vehicles are able escape the crossing. 

1.2 High-Speed Rail and Grade Crossings 

The study of grade crossing safety in high-speed rail corridors dates back to at least the early 

1970s (FRA and Federal Highway Administration [FHWA], 1972). This research addresses 

what is now known as conventional high-speed rail service or speeds up to 110 mph (176 km/h). 

The first important research that examined grade crossing safety issues at speeds in excess of 110 

mph (176 km/h) followed shortly thereafter (Hopkins, 1973). In his report, Hopkins 

characterizes the various grade crossing risk mitigation options and strategies for train speeds 

between 120 mph (192 km/h) and 150 mph (240 km/h). His recommendations include advanced 

4 
warning signals at crossings, pre-emption of nearby highway signals, four-quadrant gates, 

improvements to flashing lights at gates, constant warning time circuitry, and trapped vehicle 

detection systems. This appears to be the first report in the United States that promoted the 

usage of four-quadrant gates. 

In the years since this work was first published, FRA has extensively researched grade crossing 

safety in the high-speed rail arena. Of this vast body of knowledge, FRA published RailHighway Crossing Safety Action Plan Support Proposals (Action Plan) in 1994. In the Action 

Plan, the authors identify the following six fundamental areas for furthering the cause of grade 

crossing risk mitigation: 

• Increased enforcement of traffic laws at crossings 

• Rail corridor crossing safety improvement reviews 

• Increased public education and implementation of the Operation Lifesaver program 

• Safety and private crossings 

• Increased emphasis on data and research 

• Increased trespasser prevention 

The Action Plan also delineates three categories of high-speed rail: 80-110 mph (128-176 km/h), 

110-125 mph (176-200 km/h), and speeds greater than 125 mph (200 km/h). In terms of highspeed rail lines, the Action Plan prescribes specific treatments for public and private grade 

crossings (listed in Table 1 by high-speed rail category). 

On the NEC, the FRA Office of Safety has defined different rules for train speeds at grade 

crossings. For crossings with conventional warning systems, train speeds are not allowed to 

exceed 80 mph (128 km/h). However, the Office of Safety has also defined the requirements for 

high-speed crossings along the corridor. For crossings with four-quadrant gates and ODSs, train 

speeds as high as 95 mph (152 km/h) are permitted. In these instances, the ODS must be 

connected to the train in-cab signaling system such that a train will be brought to a stop should 

the crossing be determined to be occupied following descent of the gates. 

The Office of Safety approved this deviation from the Action Plan because of the unique train 

control system installed on the NEC. The train control functionality is performed by two major 

components: (1) the nine-aspect cab signal system that maintains vital train separation and (2) 

the Advanced Civil Speed Enforcement System, an overlay speed enforcement system. The 

Office of Safety believes that these two components will provide sufficient risk mitigation such 

that high-speed train operations will be permitted at the specially equipped crossings. 

5 
6 

Table 1. High-Speed Rail Grade Crossing Treatments 

Rail Speed Public Grade Crossing Treatment Private Crossing Treatment 

80-100 mph 

(128-176 

km/h) 

Eliminate all redundant or 

unnecessary crossings. Install most 

sophisticated traffic control/warning 

devices compatible with the location; 

e.g., median barriers, special signing 

(possible active advanced warning), 

four-quadrant gates. Automated 

devices should be equipped with 

constant warning time equipment. 

Close, grade separate, and provide a 

secured barrier or automatic device for 

private crossings. Extend device or 

barrier across the entire highway on 

both sides of the track. Should 

normally be closed and opened on 

request, if no train is approaching, for a 

period of time sufficient to cross the 

track(s). 

110-125 mph 

(176-200 

km/h) 

Protect rail movement with full width 

barriers capable of absorbing impact 

of a highway vehicle. Include a failsafe vehicle detection capability 

between barriers. Notify approaching 

trains of warning device or barrier 

failure or of an intruding vehicle in 

sufficient time to stop short of the 

crossing without resorting to energy 

brake application. 

Protect rail movement with full-width 

barrier or gate, normally closed and 

locked, capable of absorbing impact of 

a highway vehicle. Gate lock or 

control should be interlocked with train 

signal and control system and released 

by a railroad dispatcher. A fail-safe 

vehicle detection or video system 

should monitor the area between the 

barriers. The crossing should be 

equipped with a direct link telephone to 

the railroad dispatcher. 

>125 mph 

(>200 km/h) 

Close or grade separate all highwayrail crossings. Close or grade separate all highway-rail 

crossings. 
2. Literature Review 

The earliest attempt to model grade crossing accident frequency and severity dates back to the 

1972 FRA Report to Congress: Railroad-Highway Safety Part II: Recommendations for 

Resolving the Problem. The model further evolved under research performed by FHWA 

(Huntington et al., 1972; Coleman and Stewart, 1974; Coleman and Stewart, 1976) before 

reaching its final state under joint FRA and FHWA research (Mengert, 1980). Concurrent to the 

accident prediction modeling research was a separate effort to model the effectiveness of passive 

devices (i.e., crossbucks); active warning devices, such as flashing lights; and automatic gates in 

reducing grade crossing accidents (CPUC, 1974; Morrissey, 1980). 

FRA culminated this research with the publication of the Rail-Highway Crossing Resource 

Allocation Model (DOT model) in 1981. After further research (Eck and Halkias, 1984; Farr and 

Hitz, 1985), the model was refined, and the revised version was published in 1986 (Farr, 1986). 

The two primary inputs to the model are the DOT accident prediction and accident severity 

formulas. The resource allocation model was developed to prioritize crossings by risk and 

severity to evaluate the societal benefits of grade crossing improvements, such as warning lights 

and automatic gates, within a selected group of crossings (i.e., all crossings within one state). By 

using a risk-based approach for estimating the effects of higher train speeds on grade crossing 

safety, Mironer et al. (2000) showed that the highest speed crossings in a corridor are not 

necessarily the highest risk crossings. 

 

2.1 Previous Four-Quadrant Gate Studies 

The first four-quadrant gate crossing in the United States began service in 1952 and has been 

operational ever since. However, the first major study of this technology was not conducted 

until 1989 in Knoxville, TN (Heathington et al., 1989). This research was performed using the 

before and after methodology of comparing the motor vehicle violation and collision rates of the 

pre-existing dual-gate crossing with the four-quadrant gate technology. The results of this 

evaluation showed that the four-quadrant gate had no impact on the level of service provided by 

the crossing and yielded an increase in safety as measured by the virtual elimination of risky 

behavior and motor vehicle violations (Heathington et al., 1989). Research resulted in the 

following major findings: 

• The four-quadrant gate system eliminated gate violations. 

• The number of vehicles traversing the crossing within 10 and 20 seconds of a train was 

eliminated. 

• The four-quadrant gate system did not appear to increase the risk of a vehicle being 

trapped on the tracks with an exit gate delay of several seconds. 

• Emergency vehicle operations through the crossing were not impacted. 

• No unreasonable delays occurred for motorists at the crossing. 

7 
Four-quadrant gates are applicable for the following types of crossings: 

• Four-lane undivided highways 

• Crossings with multiple tracks separated by a distance greater than the length of a motor 

vehicle 

• Crossings without constant time warning 

• Crossings with traffic, such as hazardous material trucks, school buses, or high-speed 

passenger trains 

• Crossings with high violation and accident rates 

In the 1990s, the Volpe Center performed another before and after evaluation of four-quadrant 

gates in Charlotte, NC. In this study, two dual-gate crossings were upgraded with four-quadrant 

gates as part of Phase I of the North Carolina Sealed Corridor program. The results over a 5-year 

post-treatment period showed that risky motorist behavior, driver violations, and fatalities were 

eliminated, compared to 4 fatalities at the 2 crossings during a pre-treatment time span of 8 years 

(FRA, 2001). 

The Los Angeles County Metropolitan Transportation Authority (LACMTA) performed another 

evaluation of a four-quadrant gate crossing with obstruction detection. This involved upgrading 

a dual-gate system to four-quadrant gates with obstruction detection on a crossing at 124th Street 

in South Central Los Angeles. The project was unique for several reasons: (1) it was the first 

four-quadrant gate installation at a U.S. light rail transit (LRT) crossing, and (2) the crossing 

operations consisted of LACMTA LRT and Union Pacific Railroad trains jointly operating on 

parallel tracks. This environment presented a confusing array of mixed mode traffic to motorists. 

The results of this study showed a significant decrease (~94 percent) in the number of motor 

vehicle violations during a 6-month period consisting of approximately 40,000 gate activations 

(LACMTA, 2000). LACMTA is in the process of duplicating this technology at approximately 

10 other locations on its LRT system. 

The Massachusetts Bay Transportation Authority (MBTA) evaluated a four-quadrant gate system 

with obstacle detection during a 9-month period in 1999. In this study, MBTA upgraded a dualgate grade crossing to four-quadrant gates on its commuter railroad line in Abington, MA. 

Although this study was performed for demonstration purposes only, it was unique because 

magnetometers, a novel technology, were employed for obstruction detection. The results of this 

demonstration program were extremely favorable in proving that the technology works correctly. 

No experiment was performed to capture changes in motor vehicle violation rates (FTA, 2001). 

2.2 Four-Quadrant Grade Crossing Modeling 

The University of Illinois (Moon and Coleman, 1999) performed an excellent analysis of fourquadrant gate crossing operating parameters. The objectives of this research were to (1) 

optimize the timing parameters of the gates for a crossing without obstruction detection, (2) 

model the changes in optimal gate parameters with the introduction of four-quadrant gate 

technology, and (3) assess the safety and operational issues associated with a trapped vehicle 

detection system. The research resulted in the following major conclusions: 

8 
• The operating parameters of a four-quadrant gate crossing should be derived from the 

traffic, train, environmental, and driver behavior characteristics specific to that crossing. 

• Motor vehicle violation rates did not significantly vary between dual-gate and fourquadrant gate models. 

Coleman and Chitturi (2002) further refined the four-quadrant gate model to include the 

following: 

• Pavement friction resulting from weather-influenced pavement conditions 

• Motor vehicle driver decisionmaking under adverse weather conditions 

• Weather-influenced pavement conditions that increase the risk of vehicle entrapment of 

near miss clearance incidents 

• The rate of grade crossing collisions or near misses as a function of vehicle volume 

The results of this work showed that concrete, asphalt, and snow-packed wet and dry pavement 

conditions did not increase risk. A significant increase in risk, however, was found for icy dry 

and icy wet pavement conditions. The revised model also indicated that an increase in the gate 

delay, or the time interval after initiation of flashing lights, significantly reduced or eliminated 

grade crossing collisions or near misses (Coleman and Chitturi, 2002). 

2.3 Motor Vehicle Violations 

Although some research of motor vehicle violations at grade crossings over the past 30 years has 

occurred, no one has developed a causal relationship between motor vehicle violations and 

collisions between trains and motor vehicles. The results of a study performed by Sanders 

(1976) showed that poor track surface conditions were the most common reason for motor 

vehicles to reduce speed at grade crossings. Shinar and Raz (1982) found that automatic dualgates with flashing lights were associated with the lowest motor vehicle approach speeds when 

compared to crossbucks and flashing lights. The Heathington et al. (1989) study of a fourquadrant gate grade crossing in Knoxville, TN, showed no significant difference in motor vehicle 

brake rates at dual-gate and four-quadrant crossings. This result was surprising until the 

Heathington team found that the platooning of vehicles driving around the closed gates impacted 

motor vehicle brake rates at dual-gate crossings. 

Meeker et al. (1997) performed a before and after study of driver behavior at a grade crossing 

initially equipped with flashing lights and then upgraded to dual gates. The results of this 

research showed that the addition of the gates decreased motor vehicle violations from 67 

percent to 38 percent when the gates were closed. Another result of this study was that drivers 

who crossed around closed gates were significantly less likely to stop or slow on approach to the 

crossing than drivers approaching flashing lights only. Tenkink and Van Der Horst (1990) found 

that some motorists proceeded to drive through a crossing after a train had passed but before the 

warning lights were extinguished. This type of scenario could increase the probability of 

collisions with trains approaching from the opposite direction and signifies the need for second 

train coming signs. Richards and Heathington (1990) found that drivers were more likely to 

commit violations when measured crossing warning times were greater than 30-40 seconds. 

Abraham et al. (1998) found that motorists were more likely to commit hazardous violations at 

9 
10 

multitrack, multilane road (grade crossings) equipped with dual-gates rather than passive 

crossings. The dual-gate crossings with the highest violation rates also had the highest accident 

rates, thereby justifying the need for four-quadrant gates. 

Fitzpatrick et al. (1997) developed two logistic regression models to predict whether motor 

vehicle drivers will commit either flashing light violations or the riskier, typically enforced 

violations, from 2 seconds after gate initiation to time of train arrival. These models can be used 

to characterize hazardous grade crossings that may require further safety improvements. The 

inputs to these regression models are train speed, number of train tracks, warning time, sight 

distance adequacy, and the number of approach lanes. In a study of gate operating parameters by 

Moon and Coleman (1999), decreasing motor vehicle speeds were measured at approaches to 

dual-gate grade crossings under consideration for upgrades to four-quadrant gates. 

2.4 Effectiveness of Four-Quadrant Gates 

Unfortunately, the operational experience with four-quadrant gate crossings in the United States 

has been extremely limited. This has precluded the collection of statistically significant data and 

the calculation of four-quadrant gate effectiveness factors in the DOT model. However, the 

initial safety data has been highly favorable; at the time of this evaluation, no collision between a 

train and an automobile at a four-quadrant gate grade crossing had occurred in the United States. 

In its notice of proposed rule making (NPRM) entitled Use of Locomotive Horns at HighwayRail Grade Crossings, FRA proposed estimates of effectiveness rates for various grade crossing 

treatments, including four-quadrant gates. FRA defined the effectiveness rate as the reduction in 

the probability of a collision at a grade crossing provided by a supplementary safety measure 

when compared to the same crossing equipped with conventional automated warning systems of 

flashing lights, gates, and bells. The effectiveness values for four-quadrant gates are as follows: 

 

 

Four-quadrant gates without obstruction detection: 0.82 

Four-quadrant gates with obstruction detection: 0.77 

 Four-quadrant gates with medians of at least 60 feet 

 (with or without obstruction detection): 0.92 

 

FRA states that these are highly conservative values based on preliminary measurements. In 

addition, installing obstruction detection equipment may cause exit gates to remain up 

indefinitely as one or more vehicles pass over the crossing or platoon through the crossing. 

Although providing obstruction detection functionality prevents vehicles from becoming trapped 

within the crossing, probability exists that some motorists will follow violators through the 

crossing, thereby keeping the exit gates raised. In situations where medians are not installed to 

prevent this situation, FRA has assumed a lower effectiveness rate. 
3. Four-Quadrant Gate with Obstruction Detection Technical Description 

The School Street four-quadrant gate system was designed to include the following subsystems: 

(1) signaling and control, (2) obstruction detection, and (3) warning devices and barriers. 

Figure 1 shows a functional diagram of these systems. The primary functions performed by the 

signaling and control subsystem include the following: 

• Train location 

• Grade crossing equipment control, such as activation of warning devices, barrier systems, 

and ODS 

• Train control as determined from the operational status of the grade crossing equipment 

In the case of the School Street equipment, the grade crossing signaling and control system is 

interconnected with the Amtrak wayside and in-cab signaling systems. Therefore, any 

compromise in the integrity of the grade crossing equipment results in a reduction of the 

signaling aspect and affects railroad operational speeds. If the train engineer fails to respond to a 

change in signaling aspect, the speed reduction is automatically enforced by the onboard train 

control system. 

The primary functions of the ODS are to detect motor vehicles that are on the grade crossing and 

determine if they are a hazard to oncoming trains. This provides the two-fold capability of 

alerting approaching trains to trapped vehicles and releasing the exit gates so that trapped 

vehicles can escape from the railroad right-of-way. If the sensors detect that the crossing is 

occupied once all four gates are fully deployed, the control circuitry will cause the exit gates to 

release. In this manner, trapped motor vehicles are able to safely exit the crossing. 

For the School Street system, six inductive loops were installed in the roadway between the 

tracks and on the roadway approaches to the crossing. Although the sensitivity of the loop 

system varies, the test team established a minimum detection threshold to reduce the false alarm 

probability. This threshold equated roughly to detection of metal objects with the cross-sectional 

area of a motorcycle (500 pounds). If the sensitivity of the loop system were increased, smaller 

metal objects (i.e., bicycles and shopping carriages), and possibly people, would be detected. 

This could, however, create an increase in the false alarm probability and be detrimental to 

railroad operations. These loops are able to detect any metal object weighing over 500 pounds 

(i.e., a motorcycle). The crossing sensor circuitry is connected to the Amtrak in-cab signaling 

train control system. If the ODS indicates that the crossing is occupied when a train is within the 

approach circuit, the in-cab signal aspect will be reduced to a more restrictive state. 

The functionality associated with the warning device and barrier subsystems includes (1) 

warning highway and pedestrian users that a train is approaching the crossing and (2) preventing 

them from entering the crossing when a train is approaching. At the School Street crossing, the 

warning devices consist of flashing lights and bells, and the barriers are the four-quadrant gates. 

Figure 1 shows a block diagram of the four-quadrant gate system at School Street. The 

cornerstone of this system is the Microlok Plus vital and non-vital control package manufactured 

by Union Switch and Signal. The vital portion of the Microlok is a microprocessor-based 

11 
controller that performs the vital functions of a relay logic interlocking. The non-vital portion, 

known as the Genisys system, is connected to a data logger that is used to record track circuit 

status, gate position, intrusion of the grade crossing equipment building, crossing flashers status, 

cab signal status, and the state of the vital microprocessor. Other components that constitute the 

four-quadrant gate system include the following: 

• Reno Agriculture and Electronics (A&E) dual channel programmable menu driven 

inductive loop vehicle detectors for quad gate railway crossings, Model C-401-R 

• Union Switch and Signal highway crossing gate mechanism, Model 950 

• Wabtec Vigilant crossing monitor, Model WEM-450 

• Harmon Audio Frequency Train Activated Circuit 

Figure 1. Functional Diagram of the Four-Quadrant Gate/ODS 

3.1 General Description 

The microprocessor-based controller monitors and controls the two entrance gates and two exit 

gates. The entrance gates function just like conventional gates employed at dual-gate crossings 

throughout the United States and are designed to fail in the down or closed position. The exit 

gates operate in the same manner as the entrance gates but are designed to fail in the up or open 

On board Train

Control/Display

s

Train

Detection

Grade

Crossing

Control

Wayside 

Train Control

Wayside Control

Passive

Warning

SIGNALING/CONTROL

WARNING DEVICES &

BARRIER SYSTEMS

Highway Users

Train & Pedestrians

Operator

Object

Sensing

OBSTRUCTION

DETECTION

Objects i n

Grade

Crossing

Object

Assessment

Wayside

Signaling

Active Warning

4QG

Lights

Bells

12 
position. The approach circuitry responsible for the activation of the warning devices at School 

Street is installed at locations 6000 feet west of the grade crossing and 6800 feet east of the 

crossing, respectively. When these circuits are shunted, the flashing lights and bells are actuated 

for 7 seconds before the deployment of the entrance gates at the crossing. A 3-second delay is 

inserted between the deployment of the entrance gates and the exit gates so that vehicles already 

within the crossing can traverse it safely. Each set of gates requires 5 seconds to achieve full 

deployment, resulting in a total time from activation of the warning devices to full deployment of 

12 seconds for the entrance gates and 15 seconds for the exit gates (Watson, 1998). 

Once a train is within the approach circuitry, it is under the supervision of the six inductive loops 

that comprise the ODS. If the ODS indicates that the crossing is occupied or is not functioning 

properly, the cab signal aspect will be reduced from Clear to Approach Medium. If the problem 

has not been corrected after 10 seconds, the cab signal aspect will be reduced to Approach. If the 

crossing still indicates occupied after a final 10-second interval, then the cab signal aspect will be 

reduced to Restricting. The locations for the reduction of the cab signal aspects were selected 

such that a braking curve could be achieved to maintain passenger safety and comfort (Watson, 

1998). 

3.2 Operational States 

The normal static condition of the crossing occurs when no trains are on the approach circuitry. 

In this state, the gates are in the open position, and the lights and bells are deactivated. As a 

vehicle enters the crossing, the inductive loops detect its presence. The loop status, either 

unoccupied or occupied, is then transmitted to the microprocessor controller and finally to a data 

logger. Other parameters that are monitored and recorded include the following: 

• Power supply status (on or off) 

• Track circuit status 

• Relay bungalow door detection and intrusion detection 

• Flashing light status 

• Cab signal controls 

When a train occupies one of the approaches to the crossing, the flashing lights and bells are 

activated for 7 seconds, and the gates are deployed as described. The gates are deployed by deenergizing the entrance gate control relay and energizing the exit gate control relay. When the 

train enters the grade crossing island circuit, its presence is detected by the inductive loops but 

overridden by the microprocessor logic to prevent the cab signaling system from stopping the 

train. The gates remain closed for a duration of 5 seconds after the train has cleared the crossing. 

They return to the vertical position through a reversal of the process described above, and the 

crossing reopens (Watson, 1998). 

The microprocessor controller is programmed to perform a health check of the 6 inductive loops 

every 15 minutes by shunting a test loop buried underneath each loop. This check, however, is 

executed only if all of the loops have not been activated by motor vehicle traffic within the 15-

minute time interval. If they have been activated, the timer is reset. If a loop fails to return to its 

unoccupied status either after detecting a motor vehicle or being checked by the microprocessor, 

13 
14 

the crossing status changes to abnormal. If this condition occurs, the exit gates become disabled, 

and the cab signaling system is no longer affected by loop or broken gate detection. This 

information is used to notify maintenance personnel of an equipment malfunction. Once the cab 

signaling system no longer receives an input from the loops, an automatic reduction in the cab 

signal aspect occurs, thereby causing an approaching train to initiate braking. In addition, the 

exit gates remain in the vertical or open position, while the entrance gates are closed (Watson, 

1998). 

The final condition of the four-quadrant gate system occurs when one or more of the gates 

become disabled. The microprocessor controller monitors the position of the gates (either up or 

down) by inputs provided by sensors on the gate arms. If the gates are not deployed within 20 

seconds after being activated, they are considered to be broken. This is considered an abnormal 

condition, and the cab signaling system no longer receives inputs from the crossing equipment 

(Watson, 1998). 
4. School Street Evaluation Plan 

4.1 Evaluation Categories 

This report presents three evaluation categories: (1) a before and after comparison of motor 

vehicle driver behavior between the pre-existing dual-gate crossing and the four-quadrant gate 

crossing; (2) an assessment of the operational performance of the four-quadrant gate system; and 

(3) user acceptance of the four-quadrant gate technology by locomotive engineers. 

The before and after comparison was performed by analysis of train movements captured by a 

video acquisition system installed at the grade crossing. The pre-existing, or baseline, data was 

recorded between July 1997 and August 1998. The four-quadrant gate data was recorded from 

January 1999 through October 2000. Due to the small size of the baseline data set, limited trend 

analysis was the only realistic option for comparing the safety of the two crossing systems. 

The improved safety offered by the four-quadrant gate crossing was determined from analysis of 

motor vehicle driver behavior captured on video. The white loops shown in Figure 2 were used 

to activate the video system during times when the train was on approach to the School Street 

crossing. Multer and Rapoza (1998) studied two types of motor vehicle violations as provided 

below: 

• Type I: Motor vehicles traversed the grade crossing after the warning lights began 

flashing but before the gates were fully deployed. 

• Type II: Motor vehicles traversed the grade crossing after the gates were fully deployed. 

For dual-gate systems, the vehicles drove around the gates. For four-quadrant gate 

systems, the vehicles compromised the gates. 

The operational performance of the four-quadrant gate system was assessed through analysis of 

non-scheduled maintenance calls performed by Amtrak at the crossing for a representative 6-

month period. The locomotive engineer acceptance of the technology was characterized by 

administering a survey to evaluate their experience and reactions as users of the crossing. 

4.2 Observational Setting 

Figure 2 illustrates the four-quadrant gate/ODS (hereon referred to as the four-quadrant gate 

system) at School Street. As described in an Amtrak report, the system is designed to provide a 

warning time of 65 to 79 seconds depending upon the direction of train travel (Watson, 1998). 

The entrance gates installed in the driving lane of traffic and the exit gates installed in the reverse 

driving lane provide a visual deterrent for motor vehicle operators and keep them from entering 

the railroad right-of-way. The entrance gates are designed to fail in the deployed or down 

position (normal railroad operating procedures), and the exit gates are designed to fail in the 

open or up position. With this type of system, motor vehicle traffic is prevented from 

circumventing deployed gates during a train movement and cannot become trapped within the 

highway-rail crossing. 

The evaluation site is a bi-directional, two-track grade crossing, located in the town of Groton, 

CT, at milepost 131.50 of the NEC system. It is a public crossing and functions as the only 

15 
16 

access point to the 27-acre Willow Point section of Groton. Although primarily a residential area 

surrounded by Mystic Harbor and Long Island Sound, Willow Point is also home to several 

businesses, including three recreational boat clubs. The majority of highway traffic through the 

crossing consists of private motor vehicles. However, during the summer, hundreds of boats are 

hauled through the 25 ft (7.6 m) wide crossing. The most recent measurement of annual 

average daily traffic (AADT) volume at the School Street crossing was 900 vehicles. Two 

railroads, Amtrak and the Providence and Worcester Railroad, operate within a range of 15-20 

train movements through the crossing per day (FRA, 1993). Before the installation of the fourquadrant gate system, the maximum train speed through the crossing was 70 mph (113 km/h), 

with a speed restriction of 55 mph (89 km/h), 1600 ft (488 m) east of the crossing for the Mystic 

River movable bridge. Although the maximum train speed through the crossing has not been 

increased since the implementation of the four-quadrant gate system, Amtrak has long-term 

plans to increase the speed to 80 mph (129 km/h). In 2000, a four-quadrant gate system was 

installed at the nearby Palmer Street crossing in Stonington, CT. Subsequently, FRA permitted 

an increase in the civil speed to the maximum allowable limit of 90 mph (145 km/h) from 80 

mph (129 km/h) at that location.
Figure 2. Layout of the School Street Four-Q adrant Gate and Video Acquisition Syste

u

17 
4.3 Motor Vehicle Violation Data Collection and Reduction 

Figure 2 shows the video acquisition system. This configuration consisted of two black and 

white cameras with infrared lights mounted on utility poles on opposite sides of the right-of-way. 

In tandem with the video acquisition system was a set of inductive detection loops for highway 

traffic counts (unrelated to the ODS loops) embedded in the roadway outside of the gate arms. 

Each video train movement was recorded from the time the approach circuit was shunted until 

the train arrived in the field of view, up to a maximum of 120 seconds. Video data were 

transmitted to a wayside computer cabinet and underwent digital to analog processing before 

being stored. Once the train movements were completely recorded, the data was transmitted by 

modem to a playback computer system at the Volpe Center. For every crossing approach circuit 

activation, the video acquisition system captured the following fields: 

• Time of event (military time) 

• Length of video event (seconds) 

• Type of train (passenger, freight, construction, or maintenance) 

• Direction of train travel (east or west) 

• Track (1 or 2) 

• Whether the gates deployed as expected (yes or no) 

• Whether the gates redeployed as expected (yes or no) 

• Type I violations (number of motor vehicles) 

• Type II violations (number of motor vehicles) 

4.4 Operational Performance 

The operational performance of the four-quadrant gate system was assessed through analysis of 

non-scheduled maintenance calls performed by Amtrak at the crossing for a representative 6-

month period. Although this was not the most exact method for assessing the reliability 

performance of the crossing technology, the approach was appropriate for two reasons. First, no 

long-term reliability data are available for this type of technology; however, given its similarity 

to conventional dual-gate grade crossing technology, no significant differences are expected in 

their reliability. Second, the amount of time required to collect statistically significant reliability 

data was well beyond the scope of the School Street evaluation. 

4.5 Locomotive Engineer Acceptance 

Locomotive engineer acceptance of the technology was characterized by administering a survey 

to evaluate their experience and reactions as users of the crossing. Since the four-quadrant gate 

crossing was implemented as a prototype technology, the locomotive engineer survey was 

employed to incorporate user feedback for fine-tuning the design of the School Street crossing. 

18 
19 

4.6 System Deployment Cost 

The system deployment cost was evaluated under the umbrella of the following broad categories: 

• Direct labor: Costs incurred for actual labor unburdened by overhead. 

• Additional labor costs: All additional labor costs, including benefits, overhead, material 

handling, travel, and per diem, as well as general and administrative costs. 

• Engineering services: Professional engineering services provided by Amtrak for design 

of the four-quadrant gate crossing. 

• Material cost: Includes items, such as the crossing controller, vehicle detection system, 

light emitting diode (LED) flasher units, and entrance and exit gate mechanisms. 

• Equipment cost: Equipment expenditures associated with the installation of the fourquadrant gate crossing, such as construction equipment. 

5. Results and Discussion 

5.1 Before and After Comparison 

The video data sets for the pre-existing dual-gate and the four-quadrant gate systems were 

normalized for gate activations in which the grade crossing approach circuitry was shunted and 

motor vehicles were present at the crossing. For each of these train movements, the motor 

vehicle violations were tabulated and classified as either Type I or Type II, as shown in Table 2. 

The violation rates per 100 train movements in Table 2 were computed as follows: 

100x

Total TrainofNumber Movements

ViolationsIType ViolationsIType Normalized = (1) 

100x

Total TrainofNumber Movements

ViolationsIIType IIType Normalized Violations = (2) 

For the pre-existing dual-gate crossing, 56 train movements between August 1997 and July 1998 

were captured on video. Of those movements, nine showed no vehicles present, thus resulting in 

the 47 train movements in the before condition. Similarly, for the four-quadrant gate system, 

4,182 train movements between January 1999 and February 2000 were evaluated. From that 

data set, 1,632 were filtered out because no vehicles were present, yielding a data set of 2,550 

train movements for the after condition. 

These results show that the Type I (59.57) and Type II (166.00) violation rates per 100 train 

movements were significantly higher when the dual-gate crossing was placed in service than 

after the implementation of the four-quadrant gate system (25.88 and 0.00). In addition to the 

four-quadrant gate data exhibiting a shift of all the motor vehicle violations from Type II to Type 

I, fewer average motor vehicle violations occurred once the four-quadrant gate system was 

placed in service. These results indicate that the four-quadrant gate technology produced a 

decrease in the risky motor vehicle driver behavior at the School Street crossing. This was 

noteworthy given that the average warning time measured at the crossing was 80 seconds and 

that the percentage of Type II violations at dual-gate crossings increases significantly for 

warning times above 35 seconds (Fitzpatrick et al., 1997). Given that the average warning time 

measured at the crossing was 80 seconds, the reduction in Type II violations at the four-quadrant 

gate crossing was considerable. 

For a significant number of the train movements in the dual-gate data set shown in Table 2, the 

video acquisition system timed out before a train passed through the crossing. The original 

design of the video monitoring system was to record until a train appeared at the crossing, for a 

maximum time of 2 minutes. However, a substantial portion of the before video acquisition 

program coincided with electrification of the NEC in Connecticut. This increased the likelihood 

that construction and maintenance vehicles within the approach circuit had activated the grade 

crossing circuitry during the train movements in which the video acquisition system timed out. 

In fact, construction activity at the crossing became so regular that the video acquisition system 

21 
was disconnected completely for two intervals of 4 and 2 months, respectively. This was the 

reason for the relatively small sample size for the before data as compared to the after data. 

Table 2. Vehicle Violations at the Four-Quadrant Gate System as Compared to the DualGate System 

Vehicle 

Violations 

Vehicle Violations per 

100 Train Movements 

Number of 

Train 

Movements Type I Type II Type I Type II 

Dual-Gate 47 28 78 59.57 166.00

Four-Quadrant Gate 2550 660 0 25.88 0.00

When only movements with motor vehicles and trains present were analyzed, the sample size 

decreased substantially, as shown in Table 3. The Type I (85.19) and Type II (3.70) violation 

rates per 100 train movements for the dual-gate system were substantially higher than for the 

four-quadrant gate system (25.88 and 0.00). These results appeared to further corroborate this 

report’s conclusion that the four-quadrant gate technology produced an overall decrease in the 

risky behavior of motorists at the School Street crossing. 

Table 3. Vehicle Violations at the Four-Quadrant Gate System as Compared to the DualGate System, with Motor Vehicle(s) and Train Present 

Vehicle 

Violations 

Vehicle Violations per 

100 Train Movements 

Number of 

Train 

Movements Type I Type II Type I Type II 

Dual-Gate 27 23 1 85.19 3.70

Four-Quadrant Gate 2128 456 0 21.43 0.00

Heathington et al. (1989) used a slightly different definition of gate violation described as 

follows: a motorist either drove around a gate in the down position or collided with the gate as it 

was closing. This is consistent with the Type II violation definition found in Section 5.1. The 

results of this study showed an average of 2.6 violations per train movement in the dual-gate 

configuration and 0.0 violations in the four-quadrant gate system. In the dual-gate configuration, 

this equates to 266 violations per 100 train movements, substantially higher than the results 

found in Tables 2 and 3. This was most likely because of the substantially higher AADT 

(14,000) at the crossing in the Heathington study given roughly the same number of trains per 

day. In addition, the roadway in the Heathington study was four lanes wide as compared to only 

the two lanes at the School Street crossing. This was consistent with the work by Abraham et al. 

(1998) showing that multitrack crossings at multilane highways experienced the highest 

incidence of motor vehicle violations. 

The results of the Los Angeles LRT study at the 124th Street crossing also reflect the findings of 

this research. Before the four-quadrant gate/ODS was installed, the Type II violation rate was 

0.26 Type II violations per 100 train movements. After the system was installed, the Type II 

violation rate decreased to 0.15 per 100 train movements, a 94 percent reduction (LACMTA, 

2000). 

22 
The Type I violation rates were also analyzed for seasonal fluctuations. A representative month 

from each season was selected, as shown in Table 4. This was reflected in the relatively small 

data set collected during the fall of 1999. These values were normalized in terms of violations 

per 100 train movements, as illustrated in the last column of the table. Although it might be 

expected that little variation would exist in the number of train movements per day, several 

factors contributed to the discrepancies between the months. First, the total number of train 

movements for each month was the resultant of a filtering process. The filter was used to 

exclude movements in which the gates never deployed, and construction or testing of the 

warning device systems was thought to have occurred. These movements were considered not to 

be indicative of normal operations at the crossing. This was especially true of the fall data set, 

which underwent the highest amount of data reduction and filtering. Second, the previously 

mentioned construction and maintenance activities in the School Street vicinity may have 

occurred disproportionately during certain months. 

Table 4. Four-Quadrant Gate Seasonal Activity 

Season Months 

Monthly 

Number 

of Days 

AADT Number of 

Train 

Movements 

Normalized 

Daily Train 

Movements 

Winter 1999 Jan-Feb 28 570 497 17.75

Spring 1999 April 24 908 427 17.79

Summer 1999 July 29 1,062 473 16.31

Fall 1999 Oct-Nov 13 662 232 17.85

Applying Equation (1) to the train movement and vehicle violation data in Tables 4 and 5, the 

Type I average seasonal violation rates shown in Table 5 were calculated. Excluding the data set 

from the summer of 1999 (11.42), fairly close agreement was shown among the violation rates. 

This result was interesting since the School Street crossing experienced the highest average daily 

traffic (ADT) of 1,062 motor vehicles during the month of July. In contrast, the high fall and 

winter violation rates of 21.12 and 17.10 per 100 train movements were recorded during periods 

of lower ADT at the crossing; 662 and 570 vehicles, respectively. One possible explanation for 

the lower July violation rate is that motorists may have been less inclined to violate the grade 

crossing during periods of peak usage or when they were towing their boats to the marina and 

therefore would have incurred a higher personal risk of loss of property. In addition, summer 

visitors to the area may be less familiar with the crossing and therefore less likely to intentionally 

commit a violation. 

23 
Table 5. Four-Quadrant Gate Seasonal Type I Violation Rates 

Season Month 

Number of 

Vehicle 

Violations 

Vehicle Violations 

Per 100 Train 

Movements 

Normalized for 

Daily Traffic 

Moment 

Winter 1999 Jan-Feb 85 17.10 3 x 10-4

Spring 1999 April 76 17.80 1.96 x 10-4

Summer 1999 July 54 11.42 1.08 x 10-4

Fall 1999 Oct-Nov 49 21.12 3.19 x 10-4

As further evidence, the August violation rate was found to be extremely close to the July value. 

This hypothesis was supported by data that showed summer was the peak season for ADT and 

traffic queues at the crossing. Additionally, the fall and winter months, which experienced the 

highest average violation rates, had the lowest ADT and traffic queues at the crossing. 

The results from this analysis were verified by normalizing the average daily violation rate for 

traffic moment as shown in the following equation: 

DailyTraffic Moment

Daily Violation Rate Normalized Daily Violation Rate = (3) 

where Daily Traffic Moment equals number of train movements per day multiplied by ADT. 

The results of these calculations, shown in the last column of Table 5, still indicated that July 

exhibited the lowest average monthly violation rate. 

For comparison, Table 6 shows a sampling of the seasonal Type I and Type II violation rates per 

100 train movements for the dual-gate system. This analysis was performed using baseline data 

collected during the months of February and April, and the first three weeks of July 1998. 

Beginning July 20, 1998, the four-quadrant gate system became active, thus precluding the 

analysis of any fall seasonal violation data. The trend analysis of the data indicates that the 

average violation rates were weighted towards the riskier driver behavior associated with Type II 

violations as shown previously. The July data exhibited the lowest violation rates of the 3 

months and increased support for the theory that motorists were engaging in less risky behavior 

during the summer when personal property loss may be of concern. 

Table 6. Dual-Gate Seasonal Type I and Type II Violation Rates 

Motor Vehicle 

Violations 

Vehicle Violations Per 

Season Month 100 Train Movements 

Number of 

Train 

Movements Type I Type II Type I Type II 

Winter 1998 February 7 3 11 42.86 157.14

Spring 1998 April 9 3 17 33.33 188.89

Summer 1998 July 5 1 6 20.00 120.00

Fall 1998 N/A N/A N/A N/A N/A N/A

24 
The motor vehicle violation data of the four-quadrant gate crossing was also analyzed in terms of 

the Type I violation frequencies for different hourly periods. The data sets used in the seasonal 

violation analysis were sorted in terms of time of day and divided into the hourly periods shown 

in Table 7. This type of analysis has been employed as a reliable method of characterizing the 

violation rates between different hours of the day at crossings (Coleman and Venkataraman, 

2001). These results showed that the highest level of Type I violation activity occurred between 

the hours of 9:00 a.m. and 3:00 p.m. This type of driving behavior indicates that more people 

were driving over the grade crossing for personal or leisure travel activities rather than activities 

associated with commuting back and forth to work. If the crossing had been used more for 

commuting purposes, then the violation values for the traditional peak commuting hours of 6:00 

a.m. to 9:00 a.m. and 3:00 p.m. to 6:00 p.m. would have experienced the highest Type I violation 

levels. 

Table 7. Four-Quadrant Gate Hourly Type I Rates 

Time Periods Number of Type I 

Vehicle Violations

6:00 a.m.–9:00 a.m. 27 

9:00 a.m.–12:00 p.m. 60 

12:00 p.m.–3:00 p.m. 76 

3:00 p.m.–6:00 p.m. 46 

6:00 p.m.–9:00 p.m. 29 

9:00 p.m.–12:00 a.m. 14 

12:00 a.m.–6:00 a.m. 12 

The Type I violations were also classified by train type as listed in Table 8. The category “video 

timed out” refers to a normal train movement that lasted longer than the 2-minute maximum time 

of the video acquisition system. The results showed that the highest number of Type I (17.86) 

violations per 100 train movements was associated with construction and maintenance trains. 

This outcome may have been skewed since maintenance and construction trains primarily 

operated during the overnight hours, when revenue service was at a minimum and motor vehicle 

drivers were more likely to engage in Type I violation behavior. 

Table 8. Four-Quadrant Gate Type I Violation Events and Vehicle Violations as a 

Function of Train Type 

Train Type 

Number of 

Train 

Movements 

Type I 

Vehicle 

Violations 

Vehicle Violations 

per 100 Train 

Movements 

Passenger 1,270 198 15.59

Freight 29 2 6.90

Construction/Maintenance 28 5 17.86

Video Timed Out 302 59 19.54

25 
5.2 Warning Time Analysis 

Since the School Street crossing does not have constant warning time functionality, the warning 

times at the crossing varied widely depending on train speed as shown in Figure 3. The Federal 

minimum warning time requirement is 20 seconds. However, the State of Connecticut requires 

an even more stringent warning time of 30 seconds. The School Street system was designed for 

a warning time range of 65-79 seconds (depending on the approach direction) and exhibited an 

average warning time of 80 seconds, right on the higher end of the operating requirement. As 

can be seen, the majority of the train events had warning times above 60 seconds. Previous 

research on dual-gate crossings (Heathington et al., 1989) has shown that, for warning times of 

60 seconds and beyond, motorists tend to drive around the closed gates, with more motorists 

committing violations as the warning time increases. This trend is also indicative of grade 

crossings with highly variable warning times, such as the School Street crossing. The fourquadrant gates, however, eliminated any associated violations. 

0.72%

47.09%

36.67%

15.52%

0.00%

10.00%

20.00%

30.00%

40.00%

50.00%

60.00%

70.00%

Warning Time Over 100

Seconds

Warning Time 80-99

Seconds

Warning Time 60-79

Seconds

Warning Time Below 60

Seconds

Percent

Figure 3. Distribution of Gate Warning Times for Four-Quadrant Gate Crossing System 

The extended warning time at the School Street crossing is a function of the overall grade 

crossing design. As described in Section 3, the long eastbound and westbound approaches are 

required to encompass the safe braking profile of a high-speed passenger train in the case of a 

trapped vehicle or any other type of compromise to the crossing. Constant warning time devices 

have since been successfully implemented at other four-quadrant gate crossings in the 

Connecticut corridor. In addition to the inherent constant warning time benefit these devices 

provide, the added benefit of less variability in warning time has been shown to yield a decrease 

in motor vehicle violations. 

26 
5.3 Operational Performance 

Since the four-quadrant gate crossing became operational in late July 1998, no unusual 

characteristics in the system performance were observed. However, Amtrak instituted several 

design changes to improve the capability of this demonstration technology during the first 

several months of system operation. It is worth noting that numerous construction and 

maintenance activities associated with the electrification and augmentation of the NEC 

infrastructure for high-speed rail were occurring within the general vicinity of the School Street 

crossing. 

One of the primary design improvements was related to the location of the control circuit (CC) 

sign at the Mystic, CT, Amtrak train station. The westbound grade crossing approach circuit 

located east of the crossing overlapped with the westbound train berth at the Mystic, CT, Amtrak 

station. Some westbound Amtrak trains making stops at Mystic were inadvertently activating the 

School Street grade crossing circuitry, thereby causing the warning system and gates to be 

activated. This issue was resolved within the first 2 months of system operation when Amtrak 

installed a CC sign as a stopping point for westbound trains (Williams, 1998). 

During the first year of operation, the video acquisition system captured numerous events in 

which construction and maintenance activities were occurring at the School Street crossing. As 

stated earlier, these activities were primarily related to electrification work and the upgrading of 

the in-cab signaling system to which the four-quadrant gate system was interfaced. As such, 

extended periods of time may have been required to complete these projects. Although a best 

effort was made to minimally impact revenue service operations, it is probable that some of these 

construction and maintenance activities did result in unwanted grade crossing operations. Two 

indirect measures of the effect of the construction and maintenance activities were the number 

and duration of the police calls to the crossing by the Groton police department. For the 8 

months of dual-gate operation before the installation of the four-quadrant gate system, 7 

extended gate down times were recorded. These events ranged from 8 to 74 minutes, totalling 

212 minutes. These times were recorded beginning with the dispatch of the patrol officer to the 

crossing to the time the crossing was cleared and reopened for service. For the 17 months after 

the installation, police officers were called to the crossings 26 times for extended gate down 

times. These events ranged from 1 minute to 4 hours and 32 minutes, totalling 870 minutes. 

A list of non-scheduled maintenance calls to the crossing for a representative post-evaluation 6-

month period was obtained from an FRA Region I staff report (Sottile, 2001). Of the 18 

maintenance calls documented by Amtrak during the period, 39 percent (7/18) were not 

attributed to a specific grade crossing failure and may have been false alarms. Additionally, 64 

percent (7/11) of the remaining 11 maintenance calls were caused by maintenance-of-way 

equipment and revenue service trains occupying the grade crossing approach circuit for 

excessive amounts of time. Although these movements may have produced extended gate 

activations, no situation arose indicating that the crossing was not functioning as designed. 

These maintenance calls should be attributed to rail operational issues instead. The four 

maintenance calls that actually required repair of malfunctioning equipment were unrelated to 

the architecture of four-quadrant gate technology. One of these, loss of commercial electric 

power, likely did not result in a failure of the grade crossing system since a backup power supply 

27 
was at the crossing. The other three were described as relay base loose, loose contact wire in 

gate mechanism, and defective track circuit. 

5.4 Locomotive Engineer Survey 

A locomotive engineer survey was administered to Amtrak engineers to characterize their 

experience and reactions as users of the School Street four-quadrant gate crossing. The response 

rate for this survey was 55 percent (11/20), and the engineers were enthusiastic about being 

asked for feedback. The results of the survey showed that 91 percent (10/11) of the respondents 

considered their understanding of the four-quadrant gate system as good or very good and that 

technical training was not required. Additionally, 100 percent (10/10) of the engineers who 

answered the question stated that no changes were required in their train-handling strategy upon 

entering the island circuit of the crossing. Finally, 73 percent (8/11) of the respondents stated 

that the four-quadrant gate system (as compared to the pre-existing dual-gate system) had 

reduced their anxiety level at the School Street crossing. 

The primary suggestion given by the locomotive engineers was to install the previously 

discussed CC sign at the crossing approach circuit located west of the Mystic, CT, Amtrak 

station. This sign, installed in October 1998, was used as a stopping point for westbound Amtrak 

trains and further increased the performance of the four-quadrant gate system by producing more 

consistent warning times at the crossing. 

5.5 System Deployment Cost 

Since the four-quadrant gate crossing is a new system, sufficient data are not available for 

determining system life-cycle costs. However, ConnDOT and Amtrak submitted system 

invoices for deployment of the School Street crossing to the Volpe Center. From this 

information, the non-recurring engineering, system procurement, and installation costs were 

extracted and documented in this report. 

 

FRA, in a unique cost-sharing agreement with the State of Connecticut, was able to finance 80 

percent of the program cost in the form of a Federal grant to the State. Financing was made 

available from the National Highway Trust Fund by means of the Intermodal Surface 

Transportation Efficiency Act (ISTEA) of 1991. Under ISTEA, the U.S. DOT “may award 

contracts and grants for demonstrations to determine the contributions that high-speed ground 

transportation could make to more efficient, safe, and economical intercity transportation 

systems.” Additionally, the U.S. DOT can fund a maximum of 80 percent of the cost for any 

project under agreement. The ISTEA legislation states that the remaining funding should be 

provided by private industry to the maximum extent possible. However, the State of Connecticut 

financed the remaining 20 percent of the cost for the demonstration program in a unique publicprivate partnership with Amtrak. 

 

The two primary contractors for the project were Amtrak and Union Switch and Signal (US&S). 

Amtrak was paid under the auspices of the 80/20 grant described above, which had Federal and 

State funding limits of $800,000 and $200,000, respectively. As shown in Table 9, the total 

80/20 grant expenditure was $922,200; the total FRA outlay was $737,800. Total system 

deployment expenditures amounted to $731,000. The other expenses shown include $67,500 for 

28 
Grant Administration by ConnDOT and a payment of $124,000 to Asea Brown Boveri, Ltd. 

(ABB) for initial engineering consultation on the program. 

In addition to the 80/20 grant program, FRA funded US&S to modify the wayside technology 

used in the Microlok microprocessor for approximately $125,000. Table 10 shows this cost and 

the final program cost of $1,047,200. Of this total cost, FRA funded approximately $863,000 or 

82 percent. 

 

The expenditures are limited to the information presented in Tables 9 and 10 and are not 

sufficiently refined to be separated into recurring and non-recurring engineering costs. 

ConnDOT has estimated, however, the four-quadrant gate technology to have recurring 

engineering or duplication costs of approximately $400,000. This value is approximately 40 

percent of the initial system expenditure (Szgedy, 2002). 

Table 9. Expenditures for ConnDOT/FRA Grant 

Cost 

($) 

Category 

Amtrak 

ConnDOT 

Grant 

Administration 

Payment for 

Engineering 

Services to 

ABB 

Subtotal by 

Government Agency 

FRA 584,800 53,800 99,200 737,800 

ConnDOT 146,200 13,400 24,800 184,400 

Subtotal by 

Cost Category 

731,000 67,200 124,000 

Total 922,200 

Table 10. Total Project Expenditures 

Cost 

($) 

Category 

80/20 Grant FRA Grant with US&S Subtotal by 

Government Agency 

FRA 737,800 125,000 862,800 

ConnDOT 184,400 184,400 

Total Expenditures 1,047,200 

29 

6. Recommendations and Lessons Learned 

The following are recommendations from the evaluation of the four-quadrant gate/ODS 

demonstration based on lessons learned. 

6.1 Benefit Analysis to Support Effectiveness Values of Four-Quadrant Gates 

In the Locomotive Horn NPRM, FRA states that the estimates of effectiveness for four-quadrant 

gate systems are conservative. Because of the limited experience in the United States with fourquadrant gate systems, it has been difficult to accurately quantify the effectiveness values for this 

technology. Most of the data that has been collected was obtained from the two four-quadrant 

gate systems installed under the North Carolina Sealed Corridor program. As with School Street, 

this study measured the reduction in gate violation rates, not the actual changes in train-motor 

vehicle collisions. As such, it is very difficult to correlate the relationship between gate 

violations and collision risk for determining the effectiveness value of a grade crossing 

treatment. This has been a topic of discussion within the grade crossing safety industry because 

of the concern that this type of analysis will either lead to an over- or under-estimation of grade 

crossing collision risk. 

The authors of this report recommend a benefit study to characterize the true effectiveness of 

four-quadrant gate crossings. One measure that is often used to estimate the effectiveness of 

grade crossing treatments is the increase in the average number of seconds before the arrival of a 

train at a crossing in which violations occur. To date, little research supports the correlation 

between these close-call collision events involving trains and motor vehicles. However, 

empirical data from grade crossing accident reports suggest that most collisions arise from 

motorists attempting to circumvent grade crossings. If this is the case, then crossings with higher 

than average close-call collision events will benefit from four-quadrant gate systems. 

The type of study recommended above is best performed using the before and after approach of 

baselining supposed high-risk crossings in terms of close-call collision events, motorist behavior, 

and measuring the reduction resulting from four-quadrant gates. This type of research will 

support FRA efforts to better quantify the effectiveness of four-quadrant gate systems and may 

eventually lead to more widespread implementation of this technology. 

6.2 Comparison of Four-Quadrant Gate Systems with and without Obstruction Detection 

Functionality 

As stated previously, FRA is collecting data in support of the rulemaking process for locomotive 

horns. The proposed rulemaking contains estimated four-quadrant gate effectiveness values for 

systems with and without obstruction detection. However, these values are only estimates and 

have not been corroborated with actual data. Experience in the United States with four-quadrant 

gate technology has been so limited that little real data exists to substantiate any of the 

effectiveness values documented in the Locomotive Horn NPRM. A long-term study of fourquadrant gate technology with and without obstruction detection functionality is recommended 

to determine better-defined effectiveness values. 

31 
The basis for this discussion is that ODSs possess inherent properties that may increase the risk 

of train-vehicle collisions under certain conditions. The Locomotive Horn NPRM discusses two 

such conditions. One relates to the coordination of roadway traffic signals with four-quadrant 

gates. For example, a stop sign at one end of a crossing may result in a queuing of vehicles onto 

the crossing itself. In this case, the ODS would keep the exit gates open to allow motor vehicles 

to clear the crossing. This action could potentially result in the exit gates remaining open for an 

indeterminate amount of time as motor vehicles traverse the crossing. In a similar vein to the 

scenario described above, the second condition pertains to the exit gates remaining open in the 

event that a motor vehicle becomes trapped on a crossing. This functionality could possibly be 

used by the platooning of motor vehicles to keep the exit gates open for an indefinite amount of 

time as they weave around the entrance gates. Thus, one potential concern is the mitigation of 

the benefits derived from obstruction detection technology and an increased risk of train-vehicle 

collisions. 

6.3 Data Collection Conditions 

As discussed previously, a significant amount of the data was collected under less than ideal 

conditions and was therefore difficult to analyze without filtering. This process resulted in a 

small before data set from the dual-gate crossing system. Two issues, one recurring and the 

other systemic, mitigated the effectiveness of the before data collection process. First, 

significant activity from railroad construction and equipment frequently occurred within the 

vicinity of the School Street crossing. This activity was associated with the installation of the 

overhead catenary system for upgrading the North End of the NEC to electrified territory and the 

overall improvement of the track infrastructure and signaling system. Much of this equipment 

consisted of high-rail vehicles and construction trains that were operating within the approach 

circuitry of the grade crossing and causing activation of the grade crossing warning devices and 

gates. During certain periods, the construction activity was so frequent that the video data 

acquisition system was shut down until the activity decreased. 

The other factor that was the cause for less than ideal conditions during the before data collection 

stage was the video data acquisition system itself. This system was designed only to operate 

during situations in which both the grade crossing circuitry was activated and a motor vehicle 

was traversing the crossing. This type of system precluded the analysis of parameters other than 

motor vehicle violations, such as vehicle queues, trains per day, and train type. A more 

sophisticated video acquisition system was used during the after data collection period. This 

system was installed at the same time as the four-quadrant gate system and was capable of 

recording all approach circuitry activations, regardless of the presence of motor vehicles. 

6.4 Develop Standard Format for Tracking How Grant Money Is Allocated 

When a State receives a grant from FRA, no mechanism is in place that describes to what level 

of detail should be documented. In the case of the School Street program, the costs were 

delineated in the broad categories of engineering, railroad forces (including labor), and grant 

administration. This made it difficult to separate the variable, or recurring, costs from the fixed, 

or non-recurring, costs. Recurring costs refer to expenditures that continue well after a project 

has been deployed and entered service. These include as a minimum costs associated with the 

operations and maintenance of the equipment. Non-recurring or fixed costs are associated with 

32 
engineering that occurs at or near the beginning of a project. These are one-time outlays and do 

not occur again during the lifetime of a project and could be amortized over the life of the 

system. Two examples include research and development and capital investments for equipment 

procurement and installation. 

The collection and characterization of cost data are important in several respects. Cost data are 

used to approximate life-cycle costs of projects, to provide inputs in benefit-cost analyses for 

planning and trade-off studies, and to evaluate the effectiveness of new technology. 

The authors recommend that, as a minimum, recurring and non-recurring costs should be 

tabulated by State DOTs. Other costs that may be of value include the following: 

• Government, commercial, and consumer 

• Sunk or legacy system 

• Shared 

• Private partner 

• Cost baseline and base year 

33 

7. Conclusions 

The results of this investigation were extremely favorable in terms of the safety benefits and 

operational performance provided by the four-quadrant gate system. A comparison of the fourquadrant gate and the pre-existing dual-gate crossing systems was performed by assessment of 

video data collected during a 3-year period. The analysis showed that the four-quadrant gate 

technology provided an increase in motor vehicle driver safety performance at the School Street 

crossing, given similar exposure levels. The primary supporting evidence for this conclusion 

was the 100 percent reduction in the riskier Type II violations by motorists at the four-quadrant 

gate crossing, compared with Type II violations at the pre-existing dual-gate crossing system. 

Furthermore, the four-quadrant gate system yielded a decrease in the frequency of Type I 

violations. 

A similar comparison of the seasonal violation rates for the School Street crossing substantiated 

the conclusion that the four-quadrant gate system precipitated a decrease in the risky behavior of 

motorists. In addition, motorists exhibited the least risky behavior during the summer in spite of 

the fact that it was the peak season for motor vehicle traffic and traffic queues. 

The analysis of the hourly violation rate for the four-quadrant gate system found the midday 

hours to be the highest. In contrast, the standard commuting hours of 6:00 a.m. to 9:00 a.m. and 

6:00 p.m. to 9:00 p.m. yielded considerably lower violation rates. This type of driving behavior 

indicates that more people were driving over the grade crossing for personal or leisure travel 

rather than travel associated with commuting back and forth to work. A complementary analysis 

by train type found that maintenance-of-way and construction trains produced the highest 

violation rates. 

The analysis of the operational performance of the School Street four-quadrant gate system 

indicates that the technology performed as designed and required few post-installation 

modifications. The most likely cause of highway delays from extended gate activations was 

found to be maintenance-of-way railroad vehicles and revenue service trains occupying the grade 

crossing approach circuits for long periods of time. This was an operational concern and not an 

issue exclusive to the design of four-quadrant gate crossings with this architecture. 

The survey of Amtrak locomotive engineers who operated trains through the crossing provided 

positive user acceptance of the four-quadrant gate system. In the survey, the locomotive 

engineers stated that the four-quadrant gate system reduced their anxiety level and did not impact 

their train-handling capability. 

35 

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39 

Appendix 

41 
42 
43 
44 
45 
46 
Acronyms 

AADT annual average daily traffic 

ABB Asea Brown Boveri, Ltd.

Action Plan Rail-Highway Crossing Safety Action Plan Support Proposals

ADT average daily traffic 

CC closed circuit 

ConnDOT Connecticut Department of Transportation 

DOT Department of Transportation 

FHWA Federal Highway Administration 

FRA Federal Railroad Administration 

ISTEA Intermodal Surface Transportation Efficiency Act 

LACMTA Los Angeles County Metropolitan Transportation Authority 

LED light emitting diode 

LRT light rail transit 

MBTA Massachusetts Bay Transportation Authority 

NEC Northeast Corridor 

NECTP Northeast Corridor Transportation Plan 

NPRM notice of proposed rulemaking 

ODS obstruction detection system 

US&S Union Switch and Signal 

47