Small plug-in electric vehicles (PEVs) are typically said to be designed for use within cities where commutes are shorter and pollution is high.  These vehicles are targeted at large urban areas, and our analysis of PEV sales by Metropolitan Statistical Areas confirms that big cities are indeed seeing the highest sales.  This urban focus, however, raises the question: How many more cars can cities absorb?  I have broached the subject of peak cars in the past, and I stand by my assertion that the United States hasn’t yet hit that magic number, beyond which car sales will fall steadily over time.  Even more intriguing is a related question: Will PEVs actually cause traffic congestion and bring the point of peak cars sooner?

Texas A&M’s Transportation Institute released its annual study on traffic in the United States in early February.  The headlines are unsurprising: traffic is bad and getting worse.  Another recently released U.S. study, authored by Chris McCahill and Norman Garrick and published in Urban Design International, shows that once all these cars arrive at their destinations, cities that provide ample parking may not, in fact, be places where people want to be.  The amount of space required for parking cars (regardless of drivetrain) makes destinations less desirable.

More Lanes, More Traffic

As cities grow, one thing becomes clear: this is an interesting conundrum for city and transportation planners who don’t want cars but want the people that cars bring.  Often public transit is pointed to as a key solution and it does serve the purpose.  However, as I pointed out in my peak cars post, in the United States transit passenger trips and the number of vehicles sold actually correlate surprisingly well (they both grow at similar rates).  Similarly a 2011 study from the American Economic Association demonstrates that, regardless of the increase in public transit and in the number of lanes of roadways, traffic tends to always clog the available roads.

In sum, traffic is getting worse (and perhaps more concerning is that it’s becoming less predictable), resulting pollution is significant, building more roads doesn’t reduce traffic, and when all that traffic arrives at its destination, if drivers can easily find a place to park, that likely means they don’t want to spend much time there.  To find the solution to this challenge, a number of different strategies for congestion mitigation have been attempted, including congestion pricing, banning vehicles from roads on specific days, increased public transit, and carsharing.

Since congestion mitigation is almost always centered on the environmental impact of traffic, it makes sense that PEVs would be excluded from mitigation schemes.  PEVs greatly reduce or eliminate the environmental cost of traffic.  Of course, the fly in the ointment is that many of the other indirect costs of driving a vehicle remain ‑ particularly time lost to traffic congestion and increased parking space requirements.  While this won’t matter for the next decade because of the low number of PEVs on the roads, as the market matures expect to see PEVs increasingly getting lumped together with traditional vehicles.  This distinction matters because city and transportation planners talk in terms of decades in future plans … much to the bicycle industry’s glee, no doubt.