Infrastructure for Congestion Pricing in Urban Environments

May 17, 2022
Michael Kolb &

Traffic jam of cars on a New York City bridge.

Traffic congestion is something everyone hates. Unfortunately, vehicle gridlock has become a way of life, especially in dense urban cores around the U.S. Indeed, the average American driver loses 36 hours annually due to congestion, costing $564 per driver in wasted time, according to the 2021 Global Traffic Scorecard. We’re collectively wasting time and money sitting in traffic.

Over the past decades, our solution to traffic congestion has been to build more roads, but that isn’t always the right solution for dense, urban districts with limited space for additional roadside infrastructure. Modern transportation planning now includes emphasizing a multimodal approach for road improvements to facilitate equitable means of getting around. It also can alleviate congestion by providing alternate transportation methods like public transit, rail, and even bicycling to get cars and trucks off the road.

What is Congestion Pricing?

Congestion pricing, sometimes known as congestion charging, is another gridlock-relieving initiative becoming a reality in various metropolises. Congestion pricing in urban areas minimizes traffic congestion in a city center or central business district by charging individuals who use those clogged roadways a fee without the need for toll booths. Pricing structures can vary by time of day, or they may be set using “dynamic” pricing algorithms based on actual traffic volumes to influence potential road users’ route choice and departure time behaviors.

In addition to the policy aspects of congestion pricing, there are infrastructure technologies in which firms like Gannett Fleming are interested. Devising the planning and implementation strategies for congestion pricing pairs state-of-the-art technology with solid tolling infrastructure of cameras, sensors, and antennas. It’s a challenging system design that must consider the hardware impacts on dense and often historic city centers while accurately capturing and disseminating data of thousands of daily vehicles.

Congestion Pricing in Practice

For any congestion pricing program, the overarching business rules and requirements must be defined to design and implement an effective and accurate solution. For example, London’s congestion charging program is the most widely known and often used as a model to follow. London began with the basic premise that all congestion charge payments are made in advance or shortly after a trip. The city initially provided a variety of methods to facilitate payments – web, retail outlets, kiosks, and later added mobile apps. Thus, the technology deployed on the roadway itself was used for enforcement and not generating toll charges.

Cameras overlooking a community.Cameras deployed throughout the congestion zone needed to capture only a single image of a vehicle and compare it to the list of payments received. If the vehicle’s plate isn’t on the list, the system deems the vehicle a violator and mails a fee. Cameras are linked to an approved time source to ensure that images captured are reliably timestamped for evidentiary purposes, ensuring only those in the zone during charging times receive a notice.

Over 90-95% of the London congestion zone trips are prepaid, so revenue losses are minimal, even during technical outages. This allows the city to deploy a cost-effective, camera-only solution with equipment deployed strategically to maximize enforcement without covering every vehicle trip. Nonetheless, hundreds of cameras are deployed at the border of the zone and throughout the zone. In addition, London also uses mobile cameras to help capture movements within the zone.

London’s system benefits from a single motor vehicle agency for Great Britain with a single license plate style, unlike any U.S.-based congestion pricing system that must accommodate 50-plus state jurisdictions and multiple plate types.

Swedish tolling lanes.In Sweden, Stockholm’s congestion charges began as a pilot program, testing alternatives to business rules and technology. The initial deployment used a combination of Automatic License Plate Recognition (ALPR) cameras and radio-frequency identification (RFID) readers and transponders to charge customers. The equipment layout followed a typical open-road tolling zone approach with three gantries – the first supporting rear-plate cameras, the middle for overhead sensors and RFID antennas, and the third for front-plate cameras.

The pilot program revealed that the RFID system was not a necessary component, and the current approach does not use RFID to charge customers. As with London, Stockholm has the advantage of only a single motor vehicle agency for the country and a single license plate style that technologies need to accommodate.

Congestion Pricing in New York City

Map of the New York City Central Business District Tolling Program.Arguably one of the most anticipated congestion charging projects is in New York City, known as the Central Business District Tolling Program. Congestion charging has been discussed for New York City for several decades, and an earnest attempt was made 12 years ago at the local and state levels, but legislative and funding hurdles thwarted progress. However, in April of 2019, with the passage of the Metropolitan Transportation Authority (MTA) Reform and Traffic Mobility Act, the basic high-level business rules of the program were put into law. Boundaries of the central business district were determined, along with limited tolling exemptions, including emergency vehicles, vehicles carrying people with disabilities, and lower-income drivers.

In March 2019, MTA Bridges and Tunnels issued a request-for-proposal (RFP) for a congestion charging system with an exhaustive set of requirements to address the challenging New York City environment, allowing vendors to provide innovation in meeting the requirements. An important differentiator compared to London or Stockholm was the pre-existence of a toll system – E-ZPass. E-ZPass is one of the most well-known electronic tolling programs globally and enjoys extremely high usage rates in the New York City area. There are over 56 million valid E-ZPass transponders in circulation, including 20 million issued by New York and New Jersey. The Lincoln Tunnel connecting New Jersey to the central business district has over a 90% E-ZPass share, with the Holland Tunnel not far behind at 89%. And, at the Queens Midtown tunnel, E-ZPass share exceeds 95%.

The resulting solution to be implemented in New York City will rely on E-ZPass as the primary method of charging and collecting fees, with the existing Tolls by Mail program used to video toll others. Other requirements included avoiding in-ground sensors to reduce the impact of installation but also recognizing the challenging conditions of New York City streets. This led MTA to look for a solution that supported shape-based vehicle classes.

TransCore all-in-one detection sensor.TransCore is developing the Central Business District Tolling Program. It uses an all-in-one detection point unit over each lane that incorporates all sensors into a single, easy-to-install and swap-out housing with shared toll zone equipment located in a cabinet mounted to the support pole. The lane equipment is either mounted overhead for coverage of multiple lanes, side-fired for a single lane, or a combination on both sides of a roadway. This maximizes existing street infrastructure such as light poles and other overhead structures.

Vehicles driving on a busy city street.
Design not yet installed and subject to change.

Each unit contains four cameras:

  • One pair for front and rear vehicle detection and classification.
  • One pair for front and rear license plate capture.

The classification cameras use Artificial Intelligence (AI) technologies to examine the video stream and identify individual vehicles. It matches their shape to the defined classification scheme for assessing the correct charge. Likewise, the license plate cameras use AI to extract the plate number, plate state, and, if necessary, even plate type to ensure the correct vehicles get charged. The E-ZPass reader employed is capable of reading each of the three RFID protocols identified as necessary for national interoperability:

  • The transportation demand management protocol used by E-ZPass.
  • The 6C protocol now being used in California and other parts of the country.
  • The SeGo protocol that dominates in the central U.S. and Florida.

Other tolling technology vendors have been working on approaches to support congestion pricing in an urban setting. Kapsch has a system that includes a slim, single gantry approach that is far less intrusive than a traditional open road tolling zone. The single gantry supports cameras, RFID antennas, and overhead sensors necessary to detect and charge vehicles crossing underneath. There’s an even less obtrusive pole-mounted solution for narrower roadways that incorporates cameras and RFID. Finally, an app-based approach can support fixed-fee charges and charges that can vary by time of day, as well as mileage-based charging that can easily adapt to changing charging zones via software. However, as with GPS-based tolling in general, an app-based solution still requires enforcement infrastructure for those that refuse or neglect to use the app.

Busy city street with vehicles passing under a tolling structure.
Image courtesy of Kapsch TrafficCom USA.

Conduent is another technology vendor whose approach avoids any gantry structures and relies on pole-mounted cameras that, like TransCore’s solution for New York City’s Central Business District, uses AI techniques to detect and classify vehicles based on their shape and extracts license plate data for upstream processing and charging of customers. A single-pole approach is used for narrow or medium-sized streets, and installations on both sides of the roadway cover wider streets. The system constantly scans for vehicle and plate data using multiple cameras to avoid obstructed vehicles and plates.

Conduent camera and captured images of vehicles and their license plates in traffic.
Images courtesy of Conduent.

Gannett Fleming’s Congestion Pricing Future

As technologies advance to facilitate congestion pricing in the U.S., so do the policy efforts to bring these programs into urban cores. Elected officials in Los Angeles, Seattle, and Portland are considering congestion pricing to ease gridlock while also raising money to improve aging transit systems.

MTA selected Gannett Fleming to be a peer review consultant for the New York City Central Business District Tolling Program, which includes assistance in developing the RFP, reviewing vendor proposals, reviewing system design, and participating in system testing. Drawing on the firm’s stellar reputation and decades of experience in tolling and managed lanes, the team working with the MTA is helping steer New York City into a cutting-edge tolling system that will increase revenue and decrease congestion to the Big Apple’s clogged roadways.