Wednesday, February 11, 2015
Driving . . . Faster
Utah and Idaho (at least) have raised some interstate speed limits to 80 mph. Unfortunately, they did that since I was last in Idaho.
I've often thought the speed limit on I-90 between Ellensburg and Sprague here in Washington State should be 80 mph (it's now 70).
But (except maybe in Montana) speed limits are not set for convenience and safety, but to maximize revenue. Michigan did a study and found that raising speed limits from 55 to 70 increased safety. Why? Because with a 55 mph speed limit, the speed differences between cars was as much as 20 mph (some were going 55 or slower, some were going 75 or faster). Raising the speed limit to 70 meant fewer cars were going slow so the speed difference between cars (a large factor in automobile crashes) decreased. And the average speed on the road with the 55 mph speed limit was 74 mph. With a 70 mph speed limit, it was 72.
A study also found that it's safer to drive faster than traffic then slower than traffic. You're more likely to be in an accident at 10 mph under the speed limit that at 10 mph over the speed limit. But who gets tickets?
Now, admittedly, I like to drive fast. But I try to drive fast responsibly. I used to drive on a racetrack but the costs got to be too much. Not so much the fees, but the replacement costs of tires and brakes which you wear out very fast on a racetrack. So if I do drive fast I pick empty roads. Luckily, where I live, there's a few of those. Unfortunately, they tend to be straight and taking curves fast is so much more fun.
And now maybe I'll have to find an excuse to go to Montana. There's this curvy part of I-90 between the Idaho border and Missoula . . .