Chapter 12: Urban Transportation Policy “Everything in life is somewhere else, and you get there in a car.” E. B. White, One Man’s Meat, (NY: Harper & bros, 1942).

Related Concepts  Infrastructure  Public Good  Natural Monopoly

Traffic Congestion

Traffic vs. Traffic Flow  Added autos reduce stopping distance and limit one’s ability to enter the highway or switch lanes.  Without an accident or bottleneck, complete gridlock is very unlikely.

Externalities from Congestion  As a road approaches capacity, each new auto slows all cars on the highway, producing external costs and a deadweight loss from overuse.  Externalities from congestion include the time and money costs of delay, an increased risk of accidents, and noise and air pollution.

Table 12-1: Sources of Traffic Congestion Source of CongestionPercent of Total Bottlenecks40% Traffic Incidents25% Bad Weather15% Work Zones10% Poor Signal Timing5% Special Events/Other5% Source: Federal Highway Administration

Table 12-2: Congestion Costs per Auto *The ratio of rush hour travel time to free-flow travel time Source: Schrank, et. al, 2012 Congestion Measures per commuting driver Yearly delay (hours) Travel time index* Wasted fuel (gallons) CO 2 per auto (lbs) Congestion cost (2011$)$342$795$810$818

Highway Safety  Total fatalities have fallen despite greater miles traveled.

Policy Alternatives

New Highway Construction  Highway construction increases capacity, but also leads to “triple convergence” and relatively little long term effect on congestion.

Example: Boston’ “Big Dig”  Boston’s Central Artery project (known as the “Big Dig”) involved replacing an elevated 6 lane highway with an underground multi-layer 8 to 10 lane route directly beneath the original road.  The Big Dig project was under construction from 1991 to The total cost for the Big Dig project totaled approximately $15 billion, or nearly $2 billion per mile.  The effect of the Big Dig project on congestion is unclear. The Tom-Tom Congestion Index says Boston had only a 10% average highway delay, but the Federal Highway Administration ranks Boston as the 6th most congested city in the U.S. in 2013 with a 25% average peak period delay.

Congestion Fees  Fees or taxes for rush hour driving such as in Singapore or through HOT lanes reduce rush hour demand while not directly affecting off peak travel.

Urban Mass Transit MARTA rail, 2004 and  Proposed plans to add a ring rail line to Atlanta’s MARTA rail system are still being considered, but have not yet been completed  A light rail loop route is possible in the future

MARTA expansion concepts

Update on MARTA  As of 2014, MARTA has divided its expansion plans into a number of smaller initiatives, ( most of which are still in the evaluation stage.  As of 2015, MARTA’s heavy rail map is identical to the 2004 map reproduced earlier.

Conclusion  The primary lesson of this chapter is that some policy problems have a large number of possible solutions. The problem of traffic congestion can be improved temporarily or permanently by increasing the supply of highway lanes, decreasing rush hour demand through fees and taxes, encouraging car-pooling through regulations, increasing the availability of substitutes for the automobile by subway or express bus investments, and lowering the cost of these alternatives through subsidies.