Patrick DeCorla-Souza Federal Highway Administration TRB Transportation Applications Conference

1. Establishing a Metropolitan Network of Congestion-Free FreewaysEliminating Freeway Bottlenecks in the Short-Term Without Major Construction Patrick DeCorla-Souza Federal Highway Administration TRB Transportation Applications Conference May, 2007

2. Overview • The freeway congestion dilemma • Addressing traffic flow breakdown with a new approach to transportation system operation • Costs, revenues and benefits

3. As Much as Half of Freeway Capacity is Wasted in Rush Hours SR 91 Express Toll Lanes: • Vehicle throughput is double in the peak hour • Free-flow speed vs. 15-20 mph in free lanes

4. 5:00 a.m. 6:00 a.m. 9:00 a.m. 7:00 a.m. 8:00 a.m. Eastbound I-66, Northern VA – Monday Morning, March 5, 2007 Outside Capital Beltway

5. Travel Time on Eastbound I-66: 7am to 10 am

6. Travel Time with No Flow Breakdown(for the same 19,000 vehicles) *Previous freeway traffic only. Recovered capacity of 5,000 vehicles will attract additional drivers

7. Annual Benefits of Free Flow on I-66 *Additional benefits anticipated 9 – 10 am due to recovered capacity (5,000 vehicles), including: (1) benefits to 5,000 vehicles; (2) congestion reduction on alternative routes. **At $12 per hour

8. The Problem is Solvable • Keeping a small number of vehicles from arriving at critical times can prevent flow breakdown • Evidence: • Washington DC in August • State holiday in California • Jewish holiday in Boston • In each case less than 10% fewer vehicles

9. Can a Few Vehicles Shift Arrival Time? • National Household travel Survey: • 20% of vehicle trips made during peak travel periods are made SOLELY to shop • Total non-work travel** constitutes: • 49% of vehicle trips in AM peak period • 75% of vehicle trips in PM peak period *Source: USDOT, FHWA – National Household Travel Survey 2001 ** Includes only trips not made during a commute “tour”

10. Can a Few Vehicles Shift Arrival Time? • Options for work trips: • Shift to transit • Vanpool or carpool • Use flextime, or telecommute • Key is to get a few vehicles off the freeway during the critical period

11. Can We Prevent Flow Breakdown? • The three “pull” strategies (transit, ridesharing and flextime/telecommuting) are necessary but not sufficient: • Any reduction in delays due to such shifts will cause “replacement” of reduced traffic by those who had previously been deterred by congestion • Must ensure that user-borne cost of driving stays about the same as before • Two ways: (1) ramp metering; (2) congestion pricing

12. (1) Ramp Metering • Controls merging traffic at freeway entrance ramps, using time delay as a “price” to enter the freeway • Main issues: • Queues can back up onto arterials and cause congestion • Drivers frustrated by long waits • Those living further out have advantage over those living in central city • Motorists may choose to divert to alternate routes

13. (2) Congestion Pricing • Variable toll “price” to manage demand for use of freeway: • Unlike time “price” in ramp metering, user-borne toll cost is not a “wasted” resource – revenue can generate additional benefits • Main issues: • Motorist perceives that “free” service will be taken away • Some drivers may be made worse off

14. (3) “Super HOT” Congestion Pricing • Toll-bypass lane plus modal choices, gives options : • Wait in toll-bypass lane and “pay” with time • Go to transfer area and take fast, discounted transit • Ride toll-free in a certified vanpool or carpool • Pay variable toll and get guaranteed premium service • Pay lower tolls or no toll by traveling earlier or later

15. “Super HOT” Pricing • Dynamic pricing: • Can manage flow for optimum throughput in real time • Can respond immediately when spare capacity is available by reducing toll rates, benefiting the motorist • ALL lanes priced: • When only one or two lanes are priced, tolls must be high enough to “price off” a majority of users • When all lanes are priced, only about 10% of users must be priced off at the critical “breakdown” time– so tolls are a lot lower, and 90% are willing to pay them

16. “Super HOT” Incident Management • Overhead lane controls at short intervals: • During incident, one “clear” lane restricted for buses and HOVs • Any spare capacity in the restricted lane managed for free-flow using an “additional” variable toll for SOVs willing to pay for premium service • All other vehicles credited with amount of toll paid, if guaranteed speed is not experienced

17. Toll-Bypass Lanes • With 10-15% of travelers shifted to other modes or times-of-day, all remaining vehicles could be accommodated, so toll-bypass lanes would have zero delays to begin with • This would encourage more drivers to use the lane, until the queue is long enough that queue-delay “cost,” as perceived by those with the lowest value of time, would be equal to the toll rate • Assuming a 5 min. queue delay, and a queue discharge rate of 15 vehicles per min., the toll-bypass lane would need to accommodate 75 vehicles

18. “Super HOT” Concept Summary • Manage traffic flow on all lanes of a freeway • Variable tolls: • At bottleneck locations only • During peak periods only • Complementary strategies • Operations – ramp metering, toll collection, lane controls • Discounted transit services • Certified vanpools and carpools – toll-free • Telecommuting and flextime • Multi-modal traveler information

19. Advantages • Reduces congestion nowonwholefreeway network • Creates an HOV network and a “fixed guideway” transit network practically overnight • Advantages relative to priced lane networks: • Costs lower– less right-of-way, pavement, easier freeway-to-freeway connections • Capacity per lane higher • Safety –less weaving • User cost - lower toll for premium service • Entire facility congestion-free

20. Feasibility of a Super HOT Highway Network • Toll rates • Costs to implement • Revenues • Social benefits

21. Prototypical Urban Network • 100-mile, severely congested freeway network, avg. 6 lanes • Price all lanes – peak periods only • New express bus services with heavily discounted transit fares • Park-and-ride at transit transfer sites • Toll-bypass lanes at toll gantries at about 5-mile intervals

22. Average Peak Period Toll Rate for 10-mile Freeway Segment *Based on average value of time of $12.00, 50% of travelers value their time equal to or higher than $12.00 per hour

23. Annual Highway Costs for 100-mile Network (million $) *Based on total capital cost of $127 million, covering operations technology and toll-bypass lanes

24. Annual Transit Costs for 100-Mile Network (million $) *Annualized cost, including annualized capital cost plus annual maintenance costs

25. Annual Costs for 100-mile Multimodal Network (million $)

26. Annual Benefits for 100-mile Multimodal Network (million $) *At $12 per hour **Freeway only – does not include potential reductions due to reduced arterial congestion

27. What This Means • Use of congestion delay to allocate scarce roadway space during rush hours costs $370 million a year • Using a “Super HOT” pricing system instead would cost only $87 million annually, and would in addition provide other economic and quality of life benefits

28. Costs vs. Revenues and Benefits (million $)

29. What This Means • “Super HOT” highway network can be financially self-sufficient • Benefits will exceed costs by a 4 to1 ratio (conservatively estimated). • Potential to get public acceptance since no one is actually made worse off – although some could still perceive differently