Here is a challenge: Try driving at or below the speed limit on Interstate 93 above Concord until you reach your destination. It is tricky. So many other drivers go faster than 65 miles per hour that obeying the law can make one feel less safe than breaking it.

Statistically, it turns out that the sensation is justified. On highways, most people will travel the speed that feels most safe and comfortable, regardless of the posted speed limit. If the posted limit is significantly lower than the average speed, then the limit itself actually decreases public safety by creating a dangerous differential in speed. Those differentials can be more dangerous than speed itself, depending on the highway.

Interstate 93 above Concord is one of those highways on which the 65 mph speed limit does not make people safer. Today the House considers House Bill 146, which would raise the speed limit on I-93 to 70 mph from Canterbury to Canada (except for the stretch through Franconia Notch, which would remain the same).

This bill will not decrease public safety (most people drive faster than 65 mph anyway), and it might just increase tourism. Passing it will reduce dangerous passings on the highway. Legislators should do it.