Guest Op-Ed: A Hotter Solution for Freeway Congestion
March 18, 2022|Patrick DeCorla-Souza, P3 Program Manager, Federal Highway Administration
After the pandemic, freeway congestion will continue to intensify around large, growing metropolitan areas, even though teleworking during the pandemic may have temporarily slowed or even halted this steady increase. In fact, an increase in teleworking could increase congestion on freeways, as teleworkers are able to seek larger homes farther removed in the exurbs. As auto-centric development continues, those who don’t drive have significantly reduced mobility options, especially when it comes to suburban employment, which comprises a large share of metro area employment. Equitable access to suburban destinations, which is already lacking, will only get worse. With the dearth of transit options, access to suburban jobs becomes virtually impossible for those without personal transportation. Additionally, solutions that seek to lessen congestion by expanding highways, such as by adding new High-Occupancy Toll (HOT) lanes, will simply encourage further auto-centric development. And the reduced delays will induce new auto trips by those who were previously deterred by congestion, an unintended consequence that cancels out apparent advantages, as Anthony Downs discusses in Still Stuck in Traffic.
A Hotter Solution: Express transit, in combination with incentivized carpooling, can together create effective, affordable multimodal travel options that provide more equitable access to suburban destinations for everyone. Carpools and express transit could use congestion-free HOTTER lanes—lanes with High-Occupancy vehicles, Transit, and Tolls on Existing Rights-of-way—that could be created by converting existing lanes to congestion-priced toll lanes. HOTTER lanes could significantly reduce the economic waste of freeway congestion and capture as toll revenue the value thus created. Toll revenues could then be used to incentivize transit and carpool use and dramatically expand equitable mobility options in a post-pandemic world.
Part 1 – Incentivized Carpooling: According to the Federal Highway Administration, most recurring freeway congestion delay can be eliminated by reducing traffic by 10 to 14 percent. We can achieve this reduction by using cash rewards to get 10 to 14 percent of solo drivers to ride as passengers in express transit vehicles or carpools on congestion-free freeway lanes. For example, based on a recent study by the Mineta Transportation Institute, a cash incentive of $5.50 per carpool can incentivize as much as 30 percent of solo drivers to ride in a two-person carpool, resulting in a 15 percent reduction in traffic. Carpooling and incentive deployment could be made easy with mobile apps such as those identified in FHWA’s recent report on Analysis of Travel Choices and Scenarios for Sharing Rides.
Part 2 – HOTTER Lanes: One or two existing lanes could be converted into HOTTER lanes. The graphic below shows speed calculations made with and without HOTTER lanes using the Highway Capacity Manual.
With a 12 percent reduction in total freeway traffic, achieved by incentivizing former solo drivers to ride as transit or carpool passengers, traffic would flow at 56-60mph on the HOTTER lanes while speeds on the remaining free lanes would be no worse than before. Variable toll rates would balance traffic between HOTTER and free lanes to maintain speeds. Those not willing to pay tolls could either use the toll-free lanes or pick up a passenger headed to a convergent destination and travel free of charge in the HOTTER lanes while earning a cash reward. Alternatively, they could earn cash rewards by leaving their cars at home and riding as a passenger in a transit or carpool vehicle on the HOTTER lanes. Drivers would have the choice of a fast and reliable trip on HOTTER lanes, either as a carpool driver or as a toll-payer.
Tolls on HOTTER lanes would deter induced traffic and exurban development while providing revenue to pay cash incentives to transit riders and drivers and passengers who pair up in a carpool. Currently, HOT lanes created by adding new lanes take years to develop and construct, are expensive, and are financially viable only in a few heavily congested corridors in major metro areas. On the other hand, HOTTER lanes would need no new rights-of-way and little new construction and could therefore be inexpensively and rapidly deployed throughout the metropolitan freeway systems of every large metro area.
Part 3 – Enabling Express Transit: Congestion-free HOTTER lanes would allow express transit vehicles to provide speedier rides instead of being stuck in traffic. Direct access ramps constructed to and from HOTTER lanes could speed up access for transit, carpools, and toll-payers. As the metro area grows, automated vans and buses could be introduced to accommodate travel growth and keep congestion at bay. Automated vans/buses could operate in driverless mode on the HOTTER lanes, saving on labor costs, which are the largest share of transit operating costs. Human attendants could board and operate the vehicles on city streets.
Getting to a Sustainable Future: HOTTER lanes could significantly reduce the economic waste of freeway congestion. Capturing the value thus created in the form of toll revenue, they could return some of that value to the pockets of travelers who make choices that help reduce freeway congestion. They could ensure safe operation of automated public transit vehicles throughout every metropolitan freeway system and accommodate future travel growth while restraining auto-centric development patterns. They could provide new, affordable travel choices for those who don’t drive, and the choice of a fast, reliable trip for those who do. A HOTTER solution to freeway congestion could thus move us closer to metropolitan transportation systems that are safe, economically efficient, environmentally sustainable, socially inclusive, and financially viable.
The views expressed are those of the author and not necessarily the views of the U.S. Department of Transportation (USDOT), the Federal Highway Administration (FHWA), or the Eno Center for Transportation. Patrick DeCorla-Souza authored this paper in his personal capacity.