WAMU. Photo by Mr. T in DC.

On Wednesday, Diane Rehm talked traffic with Traffic author Tom Vanderbilt, Deputy US Secretary of Transportation John Porcari, and Brookings fellow Robert Puentes.

They discussed how much of the increased congestion in recent decades comes from non-work trips, like parents driving kids to work where once they walked, and because land use became more spread out. Porcari touted big stimulus projects like freeways in Southern California, but also talked about how a “transportation system” — not just roads alone — and TOD are key to mobility. Tom Vanderbilt also added that traffic congestion isn’t really that bad compared to many other nations and that 90% of roads are not congested 90% of the time.

Vanderbilt brought up the issue of congestion pricing, which Puentes said our international “competitors” are experimenting with (note the phrasing there). Porcari brought up the ICC as an example of congestion pricing, noting it’s easier to do it for new facilities than existing areas like New York. The panelists also touched on the decline in carpooling, the pros and cons of roundabouts (“modern roundabouts,” not the circles like Dupont), and distracted driving.

As for new infrastructure investment, Puentes noted that a lot of congestion comes from crashes blocking up the road network, and that we have to think bigger than just adding infrastructure. He said, “We have to stop thinking that we’re going to be b able to build our way out of congestion.” On transit, Porcari said that USDOT is encouraging new transit, streamlining the approval process, and trying to improve the cost effectiveness calculations.

Porcari arrived a few minutes late, saying that while he rode Metro to work, he “made the mistake of driving” to WAMU, two blocks from the Tenleytown Metro. When WAMU invites you to be a guest on a show, they offer a free parking pass. Not a Metro pass, just parking.

Before my last appearance on Kojo, I asked why they can’t give out free Metro passes as well; the producer noted that it’s easy for them to email out parking passes for their garage, but not to offer free Metro passes. Once Metro upgrades SmarTrip to allow people to check and reload their cards online, perhaps they should consider a program to let organizations email free ride coupons that people can redeem and load onto their SmarTrips via the Web site.