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Study: Driving to Save Time Just Slows Everyone Down - Streetsblog

Call it the rush hour paradox.

In a new study that confirms something that’s blindingly clear to anyone who’s ever gotten in a car, researchers have found that transportation planners who try to decrease travel times by making driving more convenient are basically ensuring that their communities will be choked by gridlock, and everyone will have a slower route to their destinations.

A coalition of academics from around the world modeled what would happen if all residents of a car-centric city made their transportation choices solely on the basis of how much time they would save by taking the fastest mode available to them — which, for most of them, would be a personal car. Paradoxically — but unsurprisingly — the model showed that when everyone tries to speed up their commute by hopping in the whip, they create traffic jams, slowing down average travel times about 25 percent compared to how fast they’d be if there were no other traffic on the road at all.

And thanks to the well-known law of induced demand, there’s simply no way to cut that congestion by building more lanes along the most popular routes — affirming that the only way to get rid of excessive traffic is to incentivize drivers to start using other modes of transportation by making them as fast, safe, and affordable as possible.

Surprisingly, the lead researcher behind the study, mathematician Raphael Prieto Curiel, says the paper was inspired by a long queue at a transit kiosk rather than a long wait in a traffic jam. While at a conference at Medellín, Colombia, he and his co-authors marveled at the region’s robust and speedy public transport network, but were less impressed by the 30-minute wait to pay their fares.

“We said, ‘This isn’t going to work, we need to do something different,'” Prieto Curiel said. “But then we said, ‘Wait: but do we really want to push people to use cars instead?'”

An avowed sustainable commuter himself, Prieto Curiel says that transportation planners often under-estimate the tools at their disposal to speed up transit service — like adding a contactless payment option at that over-crowded kiosk, or adding a bus rapid transit lane — while over-estimating their tools to speed up driving commutes, which quickly becomes mathematically impossible in a contained city environment.

Making transit speedier and active modes safer doesn’t mean cities have to ban cars from their streets altogether — though some think the study suggests they should. But it does suggest that cities should stop over-focusing on the rare occasions when driving really is necessary, and start thinking about how to get people where they need to go as quickly as possible on mass modes.


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