DALLAS - The conventional wisdom that more public transit means less highway congestion is wrong, the Reason Foundation
The empirical evidence does not support the claims of transit advocates that traffic congestion is either reduced when people take more annual trips on public transit, or gets worse with fewer trips on public transit, the libertarian-leaning Reason Foundation said.
"Statistical analysis of the 74 largest urbanized areas in the U.S. over a 26-year period suggests that increasing transit utilization does not lead to a reduction in traffic congestion, nor does decreasing transit utilization lead to an increase in traffic congestion," the group said.
The best correlation to congestion is how many motorists use the available highway miles, said analysts Thomas Rubin and Fatma Mansour. Increasing or decreasing the transit options available to the public makes little difference, they contend.
Traffic congestion can be reduced more effectively by increasing the number of lane-miles on existing freeways and arterial roads, the analysts said, or by adopting policies aimed reducing the number of vehicle miles traveled on the available road capacity.
"The lesson for policymakers is that policies designed to increase transit utilization are unlikely to reduce traffic congestion," the study said.
But Virginia Miller, chief spokeswoman for the American Public Transportation Association, said public transit has a proven record of reducing highway congestion.
The latest urban mobility report from the Texas Transportation Institute documented the congestion-lowering power of public transportation, she said.
"Without public transportation services, travelers would have suffered an additional 865 million hours of delay and consumed 450 million more gallons of fuel," Miller said, citing the congestion report issued in February 2013.
"Had there not been public transportation service available in the 498 U.S. urban areas studied, congestion costs for 2011 would have risen by nearly $21 billion from $121 billion to $142 billion," Miller said.
Transit should not be ruled out as a congestion-buster, Rubin and Mansour said, "but rather ...any such proposals should be greeted with skepticism, tempered in some instances by the particular characteristics of the urbanized area in question."
Regional differences do matter, the report said, noting that public transit accounts for 12.2% of the commuter miles traveled in the New York City region but only 2.2% of vehicle miles traveled in Los Angeles and southern California. The more urbanized the region, the report said, the more effective transit can be in relieving congestion.
In one of the seven case studies in the Reason Foundation report, Houston was cited as an example of how to reduce congestion by building more roads.
Houston's population grew by 59% from 1982 to 2007, the study said, but traffic congestion actually fell by more than a third due to a 36% increase in highway lane-miles.
"This feat was clearly achieved by significantly expanding the capacity of the road system," Rubin and Mansour said. "Houston has been far more successful in holding down increases in congestion than Los Angeles because it has done far more to expand its freeway system."
