Congestion, VMT Reduction & Mode Choice

Road Usage Charges (RUCs): Assessing fees based on the amount of vehicle miles or kilometers traveled (VMT/VKT) helps match infrastructure costs to the amount a vehicle is using the road. Establishing these fees creates a link between travel distance and price, creating opportunities to generate revenue for infrastructure maintenance while also impacting travel behavior. This ‘cost per mile’ approach makes travel costs more evident, can incentivize drivers to reduce total miles traveled, and can make other modes of transport more appealing. This is especially important with the growth of Transportation Network Companies (TNCs) and Mobility as a Service (MaaS) as it creates cost incentives for individuals to choose more efficient travel modes such as biking, walking and transit. Smartphones and other smart city technologies can provide the technological backbone to facilitate real-time assessment of VMT/VKT-based usage and fees.

Cordon Pricing: Charging fees for travel into areas of high congestion, such as city centers, helps ease congestion by discouraging non-essential trips into these areas. Cordon pricing can be fixed or dynamic (changing during time of day, day of week, or in relation to levels of congestion), and can be adjusted for different vehicle types to more accurately reflect their impacts on congestion in these areas.

Geometry-Based Taxes and Fees: These fees are charged based on the size of passenger vehicles divided by the number of people occupying that vehicle. Large, single occupancy, or zero-occupancy (i.e., autonomous) vehicles that take up large amounts of roadway but transport few people would pay higher fees than smaller, more space-efficient vehicles or larger vehicles that carry many passengers. This type of fee treats roadspace as a limited resource and charges individuals by how much of that resource they occupy. It incentivizes the efficient use of the road by preferencing smaller and more highly occupied vehicles.

Empty Seat Fee or Empty Vehicle Fee - The ‘Zombie Tax’: This tax or fee is charged based on the number of empty seats within a vehicle. Given that TNCs are increasing the amount of vehicle miles traveled per capita as they travel many miles with no passengers, and that AVs would seem to mimic this model, the Empty Seat Fee would incentivize higher occupancies of vehicles by charging for seats that could have been filled but were not. This fee type could be especially helpful in incentivizing the use of shared rides. The Empty Vehicle Fee or ‘Zombie Tax’ can also charge an additional amount for having completely empty vehicles. The travel of empty vehicles is an important consideration as AVs could travel without drivers or riders, creating a burden on the transportation system while not actually moving any passengers.

Cruising Caps: Cruising caps seek to limit the amount of time a ride-service vehicle can travel within congested areas without a customer onboard. Recent reports have found that the circulation of empty TNC vehicles in popular city areas have measurably added to congestion as they circulate while searching or waiting for their next customer. New York City established a cruising cap for a congested area of Manhattan in 2019, but the rule was dismissed in December 2019 after lawsuits by Uber and Lyft. Whether New York City appeals this decision and the rulings that follow will influence the feasibility of instituting cruising caps across the US.

Vehicle Caps: Vehicle caps seek to combat congestion by limiting the number of vehicles allowed within an area. Vehicle caps can be applied according to vehicle type, with for-hire and ridesharing vehicles being typical candidates for these caps due to their fleet size and amount of time spent in congested areas. Limiting the number of licenses or vehicle permits within an area is a tool aimed at addressing area-specific congestion.

Influencing Mode Choice: Encouraging people to use new transportation often requires a multifaceted approach. Funding improved and more comfortable transit systems helps make this efficient transportation mode a more attractive and viable alternative to driving. Similar techniques can be used to encourage the use of micromobility modes where these options help provide ideal transportation system solutions. Fees gathered from personal vehicle taxes, parking fees, and micromobility permits can be used to help fund these endeavors. As new mobility technologies advance and become more widespread, the real-time data associated with these services can provide users with more accurate information on usage, costs, and time. Incorporating this data along with access to multiple transportation services into unified Mobility as a Service platforms can provide further levers for influencing mode choice in real time.

Consider Equity in Fees and Taxes: When creating fee or tax structures, it is important to consider how these charges may affect those of different income levels and needs. Whereas fixed prices for all could disproportionately affect vulnerable populations and prevent them from accessing employment and services, focusing on equitable pricing structures take these differing needs into account. Tiered or income-based fee models are a potential solution to help mitigate fee impacts to low-income populations while still addressing congestion.