Wed 21 May 2008
The personal finance blogs have been awash with suggestions on how to drive more efficiently. The foremost solution is to drive slower. Jack Caffertty at CNN.com have even gone as far to suggest that U.S. bring back the 55 MPH speed limit. At first blush, lowering the speed limit does nothing to actually benefit the the poor commuter. As is, drivers always have the option of driving slower and therefore putting a smaller dent in the wallet.
In reality, this is much harder said than done. This weekend, I drove nearly 200 miles from Boston to Western Mass and back. Since turning 30, I’ve shed a few pounds but apparently only in my right foot. I’m a slowpoke. I’m also cheap. So it should be no surprise that I turned on my way back machine and drove like I was living in the 70s. I tried to keep my speed under 60, and failed. On the most part I was still the slowest car on the road.
So while on the surface it seems almost absurd to mandate a speed limit for greater fuel efficiency when every driver has the option of driving slower, the fact is it’s often difficult for drivers to do so. Traffic operates more efficiently when the majority of the cars cruise at about the same speed. Currently that cruising speed is easily over 70 MPH. As a result it’s not only difficult to drive at 55, but often times dangerous. A car driving slower than the traffic around is not much different from a car driving substantially faster than the traffic. I felt it. As I cruised at 55-60 MPH, I had cars passing me left and right. It was almost like I was weaving in and out of traffic. I had the option of staying in the left most lane, but if there are frequent exits that’s not a safer choice.
While I remain agnostic to the idea of lowering the speed limit, I do believe that a big part of the solution to the current energy crisis, and long term goal of energy sustainability is energy efficiency. Driving slower isn’t going to solve the problem, but it could be part of the solution. It’s also unclear if 55 MPH is the ideal speed as different vehicles have different optimal point.