Developing Traffic Control Strategies at Toll Plazas

Linda Brown and David R Jr McDonald and Edward J Myers
Institute of Transportation Engineers. ITE Journal

Oct 31, 2006 19:00 EST


History of Toll Roads in the United States

In the colonial period, paths were converted to roads to accommodate wheeled, horse-drawn vehicles. Lacking the authority to levy and collect taxes for the construction and maintenance of these roads, road commissioners and local governments required all adult males within their jurisdiction to provide two to eight days of road labor each year. The significant distances between communities and the sparse population frequently resulted in poor road conditions.

From the late 1760s to 1795, two methods of road financing were considered-taxation and tolls. Several colonies collected road taxes but found this method of road financing unpopular. The colonial states then turned to tolls for the financing of "turnpikes," named for the gate erected to stop road users until their toll was collected.

In 1792, Connecticut installed toll barriers on two roads to generate road maintenance funds for local towns. Also in 1792, Pennsylvania incorporated a company that began construction of the Philadelphia Lancaster Turnpike Road in 1794.1-3

During the War of 1812, Britain controlled the sea and American supplies were moved over land. This highlighted the inadequacies of the road system and resulted in additional road-building efforts at the end of the war.

Between 1830 and 1860, many toll roads were abandoned due to financial failures as road users found alternate "nontoll" routes, traveled at night to avoid toll collection, or paid with counterfeit coins.

Turnpikes also lost traffic to competing transport modes such as canals and railroads. The decline of turnpikes accelerated as state highway departments were created and, in some cases, were required to purchase turnpike companies that owned or operated turnpikes on the state highway system.4-5

In the 1920s and 1930s, several new roads, tunnels and bridges were designated as toll facilities to provide construction financing.6 Noteworthy projects from this era include the Holland Tunnel (1927), Lincoln Tunnel (1937) and Golden Gate Bridge (1937).

In April 1939, the Federal Bureau of Public Roads published Toll Roads and Free Roads, which examined the feasibility of a national toll road system and recommended that it not be constructed on the basis that the roads would not carry sufficient traffic to cover the cost of construction and maintenance.7

On October 1, 1940, the Pennsylvania Turnpike was opened to traffic. Utilizing abandoned railroad right of way and six pre-existing tunnels, and financed by President Franklin D. Roosevelt's New Deal Reconstruction Finance Corporation and the Works Projects Administration, the Pennsylvania Turnpike soon proved that toll roads would convey much higher volumes of traffic than had been estimated.

Although planners had predicted 1.3 million vehicle trips, approximately 2.4 million vehicles traversed the turnpike in the first year of operation.8-9 Construction of toll roads continued, with the opening of the Maine Turnpike (1947), New Jersey Turnpike (1951), Oklahoma Turnpike (1953), New York Thruway (1954), Ohio Turnpike (1955), Kansas Turnpike (1956), Indiana Tollway (1956), Massachusetts Turnpike (1957), Florida Turnpike (1957) and Illinois Tollway (1958).10

In 1991, the Intermodal Surface Transportation Efficiency Act (PL 102-240) increased opportunities for toll facilities to be constructed in whole or in part with federal funds.11 States and territories immediately began adopting enabling legislation and public-private partnerships began work on conceptual and environmental toll road studies on projects such as the SR 125 San Miguel Expressway in California, the Foothill/Easter Toll Road in California, the James River Parkway "Powhite Parkway Extension" in Virginia and die Southern Connector in South Carolina.12 Pilot project appropriations in the 1998 Transportation Equity Act for the 21 st Century (PL 105-206) and the 2005 Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (PL 109-59) continued the expansion of opportunities for toll facilities to be constructed.13"14

Many of these new toll facilities are being developed with electronic toll collection systems capable of identifying violators and collecting tolls from vehicles moving at highway speeds from 0 to 100 miles per hour.

The first such roadway, the New Orleans Crescent City Connection, opened in January 1989. By 2005, there were more than 5,140 miles of rural and urban toll roads, bridges and tunnels within the United States.


The Manual on Uniform Traffic Control Devices (MUTCD) was approved by the Federal Highway Administration (FHWA) as the national standard for all traffic control devices installed on any street, highway, or bicycle trail open to public travel. MUTCD documents standards and guidance for the design, application and placement of traffic control devices. The current edition of MUTCD (2003, Revision 1) does not contain provisions for traffic control devices at toll plazas or toll-managed facilities.

In January 2003, FHWA met with representatives from the International Bridge, Tunnel, and Turnpike Association to start a dialogue on how to achieve uniform and efficient traffic flow, improve safety and reduce the potential for crashes at toll plazas. FHWA decided to develop a compendium of best practices and traffic control strategies for handling traffic within these complex roadway environments.

In January 2004, FHWA initiated a study to collect information on current toll plaza practices, begin the development of guidelines and facilitate toll operator consensus on operating practices. Toll-supported roadways are becoming increasingly popular as local, state and federal transportation agencies continue to grapple with funding levels that are not keeping up with increasing transportation demands. As agencies turn to toll financing for construction of new roadways, the need for consistent toll plaza traffic control Guidelines is erowine.

In response to this need, FHWA with the assistance of Battelle, Wilbur Smith Associates and PBS&J, published a report entitled State of the Practice and Recommendations on Traffic Control Strategies at TollPlazas.V

FHWA is not expecting toll operators to immediately adopt the report recommendations; rather, it is requesting that the report recommendations be considcred during retrofits of existing toll facilities or the design of new toll facilities. In addition, some of the recommended traffic control device strategies may be considered for inclusion in a future proposed rulemaking for MUTCD.


The introduction to the Traffic Control Strategies at Toll Plazas report states that the goal of the document is to "have a consistent strategy for handling the potential points of conflict at toll plazas so that safety and operations are enhanced, better efficiency and economy of design are achieved, and motorist recognition and comprehension are improved." The authors of the recommended practice surveyed current practices of toll agencies throughout the United States before developing the report, which contains six chapters:

* Chapter 1 : Introduction

* Chapter 2: Plaza Operations and Toll Lane Configuration

* Chapter 3: Signing, Markings and Channelization

* Chapter 4: Geometric and Safety Design

* Chapter 5: Toll Collection Equipment Technology

* Chapter 6: Summary of Recommendations


Chapter 1 discusses the study purpose, problem statement, objectives and methodology in detail. The stated objectives of the study were to:

* Enhance safety (for the customer and toll employee);

* Improve efficiency;

* Increase uniformity in traffic control devices; and

* Build traffic control strategy consensus among toll agencies.

To accomplish the study objectives, a literature review on current practices and policies, a toll operator survey and a consensus-building workshop were conducted to develop a listing of recommended practices. The recommended practices contained in the report are a first step in promoting uniformity in toll facility design and operation.


Toll barriers such as the original turnpike gate were designed to bring vehicles to a full stop and force drivers to pay the toll. Multiple turnpike gates were grouped and the roadway widened to form toll plazas. Toll operators can improve air quality, reduce congestion, increase vehicular throughput and, potentially, increase toll revenues by reducing the time it takes for a customer to pay his or her toll.

Until recently, only the "closed ticket system," "closed barrier system" and "open barrier system" were in use on the majority of toll facilities. In the closed ticket system, motorists are issued tickets at entry points and the tickets are surrendered with payment of the appropriate toll at the exit point.

In the closed barrier system, a toll is collected at a specific location along the mainline of the tolled facility and on every entry or exit point that would allow access to the tolled facility but would not require passage across the toll barrier. All users who enter a closed ticket system or barrier system are required to pay a toll.

In an open barrier system, a toll is collected only at a specific location along the mainline of the tolled facility. There may be some travel paths that do not cross the toll barrier, thus allowing for "free" passage (see Figure 1).

The continuing development of electronic toll collection (ETC) systems is changing the way toll facilities are designed and operated. ETC systems collect tolls from vehicles equipped with a transponder or other recognition device as they pass under a gantry that can be placed at any point along a toll facility.

Existing ETC systems function with vehicles speeds ranging from O to 100 miles per hour. From 1989 until 2004, the percentage of tolls collected by ETC increased from O percent to more than 50 percent at some U.S. toll facilities.

Three types of ETC lanes currently are in use at existing toll plazas: dedicated ETC lanes, express ETC lanes and mixed mode lanes. Dedicated ETC lanes are located within a toll plaza alongside lanes that accept other payment types, such as automatic coin machines and cash lanes.

Express ETC lanes are partially or completely separated from the conventional toll plaza. Fully separated, express ETC lanes operated at highway speeds also are known as open road tolls (ORT). With the exception of the gantry structure holding toll collection equipment, ORT and higher-speed express ETC lanes may appear to the driver as a normal highway section with none of the standard toll plaza geometries or traffic control devices.

Mixed mode lanes are equipped for ETC and other types of toll collection, including cash. Existing toll facilities use a wide variety of methods to communicate to the driver the difference between ETC and non-ETC equipped lanes.

Recommended practices for dedicated ETC lanes include the following (see Figures 2 and 3):

* Minimization of differential speeds that may result from differences in non-stop dedicated lane and stop-andgo cash lane operations. Barriers or pavement markings are recommended to separate dedicated lanes from cash lanes for approximately one-half of the anticipated queue zone.

* The maximum posted speed for dedicated ETC lanes should be 2530 miles per hour where stop-andgo payment methods are accepted in adjacent lanes. In locations with many curves, merges and diverges within several hundred feet of the toll plaza, a posted maximum speed of less than 25 miles per hour is recommended.

Recommended practices for express ETC lanes include the following:

* Designing and constructing new express lane toll plazas to include the same number of express lanes as approach roadway lanes.

* Protecting and physically separating express toll lanes from the conventional toll plaza traffic required to stop or operate at lower speeds.

* Keeping separated express or ORT lane design and posted speeds at the same level as the design and posted speed of the approach roadway.

The second chapter also includes recommended practices for lane assignment, such as advising that all similar payment type lanes should be grouped together with ETC express and dedicated lanes located to the left of the toll plaza, attended lanes located to the right of the toll plaza and automatic change machine lanes located in the center lanes. Recommended practices for branch lanes, lane widths, ramp toll plazas, satellite plazas, reversible lanes and administration building access are included.


The lack of existing standards for toll plaza signing and pavement markings has resulted in inconsistent applications at U.S. toll plazas. As the use of ETC increases, the toll plaza environment grows ever more complex. Recommended practices for the traditional traffic engineering elements of signals, signs, pavement markings, channelization and lighting are documented in the third chapter.

Recommended signing practices encompass advanced toll plaza signing, sign spacing, locations of advance warning signs, letter type, letter spacing and canopy or toll lane signs. The focus is on controlling speed differentials and emphasizing lane use indicators. Control of speed differentials has a significant influence on toll plaza safety.

The primary concern is speed variation between adjacent dedicated ETC and cash lanes. Generally, larger speed differentials should be accompanied by greater spacing between lanes. Additional recommended practices for approach speed reduction and departure speed control are provided.

Lane use control signals, signs and pavement markings are used at mixed-payment toll plazas to align motorists with the appropriate payment lanes and minimize lane changes within the plaza area. Guidance on the use of changeable message signs to display lane collection mode information and recommended practices for use of pavement marking lane lines, gore striping and tollbooth, attenuator, or dedicated lane channelization is provided.

The use of flashing beacons installed adjacent to lane use control signals is not recommended because they may draw attention but confuse the motorist. Additional recommended practices for the use of signals and warning lights are provided.


The design of a toll plaza is determined by a variety of factors, including traffic volume, type of toll system, method(s) of toll collection, right of way, plaza location and approach roadway geometry. Although the primary objective of the report was to address traffic control strategies and applications, the influence of roadway geometries and safety design is recognized.

The design of a toll plaza approach and departure zone is important. The approach zone includes a transition area where the pavement widens at a specified taper rate from the mainline roadway to the toll plaza.

The departure zone is the area located after exiting a toll lane consisting of a recovery zone and transition area. The recovery zone is a downstream extension of the toll lanes used for driver re-orientation and acceleration. A departure transition area tapers at a specific rate until the pavement width matches the downstream roadway. Recommended practices for queue and recovery zone lengths, transition zone tapers, proximity of on and off ramps and express lane treatments are provided.

Express lane design issues include alleviating speed differentials, minimizing abrupt lane changes, safety and operational efficiency of the merge and diverge areas when approaching and exiting the toll plaza and available right of way. Recommended practices for lane placement, express lane design, access points between express lanes and cash or mixed-use lanes and for the design of the approach and departure zones are provided.

Additional recommended practices are provided for lane widths, cross slopes and toll island design, including ramparts, crash blocks, staff access points and lighting.


The tollbooth is used in manual collection lanes to protect the attendant and collection equipment from weather conditions and vehicles. The dimensions of the tollbooth installed in conventional toll plazas vary considerably. Recommended practices are provided for tollbooth horizontal clearance, height of the tollbooth floor, placement of attendant access doors and other tollbooth protection and accessibility needs.

The island traffic signal is frequently used to control the flow of traffic through each toll lane. The motorist is expected to stop at the toll collection point for payment when the light is red and exit the lane when the signal is green. Recommended practices for signal size, location, horizontal clearance and height are provided.

A patron toll or fare display consisting of a changeable alphanumeric sign mounted to a stanchion can be used to display the toll that is being assessed and or payment status. Recommended practices are provided relative to the horizontal clearance, character size and best placement location for automatic, manual, or Automatic Coin Machine/Automatic Ticket Issuing Machines (ACM/ATIM) lanes. Recommended practices for ACM/ATIM horizontal clearance, mounting height, visibility and truck accommodation are provided.

Automatic barrier gates that block traffic from exiting the toll lane until after the toll due is paid can be used for violation enforcement. Gates also can be used to stop or reduce traffic speed for the safety of attendants who must cross toll lanes while they are in use.

The implementation of ETC has created the need for a reliable and automated means of identifying violators and issuing legally enforceable citations and fines or fees. Cameras, supplemental lighting and other equipment can be used to capture images, of license plates for enforcement purposes.

Recommended practices are provided for violation enforcement systems (VES) including horizontal clearance, light impairment mitigation, lighting techniques for achieving quality camera images and the use of barrier gates with and without VES equipment.


The report concludes with a summary of all recommended practices developed in prior sections. The recommended practice effort did not reach consensus among the majority of agencies, and further research and study efforts should be pursued. Continued research and implementation of a uniform standard will lead to safer, more uniform and more efficient toll facilities.

The goal of the project was to enhance safety, improve efficiency and increase uniformity in traffic control device use while building consensus on recommended traffic control strategies for toll plazas. The recommended practices contained in the report represent a first step toward providing consistent design and operation guidance for the formation of uniform traffic control device strategies and encouraging continued discussions. As work progresses toward the development of standards and guidelines for toll plazas and priced managed lanes, this report should assist in the identification of topics for future study.

© 2006 Institute of Transportation Engineers Provided by ProQuest LLC. All Rights Reserved.

Source: Institute of Transportation Engineers. ITE Journal


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