I Can't Drive 55 - Sammy Hagar

[Mike]

I Can't Drive 55 - Songfacts

Back in 1909, the state of Washington introduced a speed limit of one mile in five minutes (12mph) in "thickly settled areas and business districts", and at one mile in two-and-a-half minutes (24mph) for rural areas.

In these early days, states could set their own upper limits and by 1972 the majority were 70mph, although ten states had a limit of 75mph, and two (Montana and Nevada) had no upper limit at all (although these are all daytime limits for cars on designated "fast" roads; trucks, other roads and nighttime driving all had reduced limits).

But then the fuel crisis intervened, and the American government was forced to do something to reduce the country's massive fuel consumption.

The answer they came up with was to enforce a maximum speed limit across the US of 55mph.

The 55 miles-per-hour speed limit came as a result of the 1973 Arab oil embargo.

However, federal legislation is not actually able to impose such a limit, so instead the government made this maximum limit a condition for their continued funding of their highways program. In other words, states had to impose the 55mph limit or the federal contribution to their road program would dry up.

In 1987, under mounting public pressure, the limit was raised to 65mph.

Following the increase, accident fatalities on roads with the increased limits went up about 30%. However, like all such contentious issues, there is an alternative view, and it's possible to seek out evidence that accidents rates actually decreased when the new limit was imposed.

In 1995, the US Government withdrew the national capping of the speed limits completely, and allowed states to set their own. Many states were immediately ready to go back to the way they were, but some were more cautious. Montana reverted to its "reasonable and prudent" limit in 1995, although somewhat surprisingly, Nevada established 75mph for its rural Interstates.

Since the 1950s, traffic engineers have relied on the 85th percentile rule. The idea is that the speed limit should be set to the speed that separates the bottom 85% of vehicle speeds from the top 15%. The 85th percentile closely corresponds to one standard deviation above the mean of a normal distribution.

In practical terms, the 85th percentile speed is slightly higher than the flow of traffic. It has been observed that vehicles traveling over the 85th percentile speed (or faster than the flow of traffic) have a higher crash risk than vehicles traveling around or modestly below the 85th percentile speed.

In theory, the speed limit should be set below the 85th percentile speed only if crash records suggest an unusual hazard that cannot be mitigated by other measures such as restriping or engineering improvements. However, in practice, speed limits in the United States are generally 5 to 20 MPH below the 85th percentile speed. This is partly due to political pressure, arbitrary laws or regulations[1], and the fact that many jurisdictions use the 85th percentile speed only as "guidance" or a "starting point."

One theory in support of 85th percentile speed limits, advanced by traffic engineers, is that drivers are, in whole, reasonable and prudent; drivers are able to discern road and traffic conditions, and thus able to select appropriate travel speeds in most cases. Therefore, even if the 85th percentile speed is above the posted limit, it can be prudent to increase the limit to the 85th percentile speed. (Note that traffic engineers do not argue that all drivers make perfect choices in all situations. Rather, they argue that the aggregate speed choices are usually reasonably safe.)

The faster you drive, the more fuel you use. For example, driving at 65 miles per hour (mph), rather than 55 mph, increases fuel consumption by 20 percent. Driving at 75 mph, rather than 65 mph, increases fuel consumption by another 25 percent.

*FYI - I find myself driving between 70-80 MPH whenever possible, hence I can drive 55, but I simply don't!