How Bruce Johnson Feels Speed Limits should be Set

brucej@pc01.lsua.edu
Feb 26, 1995

Interstate Speed Limits

Rural Interstates

I have yet to see a rural interstate that should not have a speed limit of at least 70 mph. In fact, in most cases, a numeric speed limit is unnecessary. In Louisiana, where the rural interstate speed limits remain at 65, most people travel between 70 and 80 mph. In Montana, they travel at the same speed. Of course, there are those who will drive through Montana just to go really fast. Those people will go really fast no matter what the speed limit is or in which state they are traveling. In the case of Montana, there is a "newness" factor. People are speed hungry now, because they have been held to rediculous speeds for so long. Once the newness wears off, the speeds in Montana will definitely be similar to those in other states/regions with similar topography and population density. For those of us who are old enough to remember the pre-NMSL days, speed limits did not mean that much, but, since many of them were set at or near the 85th percentile, compliance was not a major problem.

Speed Limit Psychology (applies to interstates, etc...)

In Louisiana, we have a very poor rate of compliance with 55 and 65 mph speeds. The compliance is even worse now that surrounding states either have raised (or are considering raising) their speed limits, while our legislature says they will not change limits here. Not only are people becoming accustomed to traveling at reasonable speeds legally by driving in other states (Texas and Oklahoma at this point), but the motorists here are rebelling against this state's refusal to address the issue. This will not improve until the state takes action (if it ever does). The ostrich approach does not work. People are tired of the oppression, and they see action in other states, but not here.

Urban Interstates

Speed limits, if any, should be set at or just above the 85th percentile speed, just as they should for rural interstates. People argue about congestion. As the highways become increasingly congested, the traffic slows down out of necessity. The problem takes care of itself. Drive through a large city. When the traffic is light, it goes at least as fast as rural interstate traffic. When a freeway is 8 or 10 lanes, it really goes fast. When the traffic is very heavy, the traffic slows down dramatically (sometimes to a dead stop). People will go 55 when the prevailing speed of that traffic is 55. When the prevailing speed is 75, they will go 75. In all highway driving, especially urban, I try to drive at about the median speed. In most large metropolitan areas, that is between 70 and 75 unless traffic is heavy. When I do this, I find myself literally in between packs (or clusters) of traffic. I have room to change lanes, and, I have room to "escape" if something significant happens on the road. I am in a position to minimize my risk of being involved in an accident. I ignore the posted speed in favor of this, and it has worked very well.

Wet/Dry Speed Limits

In areas where there are numeric speed limits, some people assume that these limits apply in all weather. 80 mph on a dry rural interstate is not unsafe, but during a blinding rainstorm, it is rediculous. In some states where snow is common during the winter, they have "snow" speed limits. In my opinion, it might be a good idea to have "wet" speed limts as well. This hopefully would allow for a considerably higher daytime, good weather speed limit, or for a speed law similar to Montana's. It would make more sense to me to have 80/65 (dry/wet) or 80/60, 85/60, or 85/65 as opposed to a straight 70 or 75 (or 65), which many motorists regard as applicable under all conditions.

At this time, I want to distinguish between "speeding" and "driving too fast for conditions." Often, when there is a major accident in the fog, rain, etc..., "speeding" is given as the cause. This is wrong. The cause was inattentiveness or "driving too fast for conditions." Speeding is simply driving faster than the posted limit. That is not necessarily unsafe (quite frequently it is not). Driving too fast for conditions has nothing to do with posted limits. It is always unsafe. If a speed limit is set appropriately, exceeding it would be going too fast for conditions. Maybe the dual limits would help. In some states, there are day/night limits.

Day/Night Speed Limits

These have merit in some places as well. Of course, our visibility is reduced at night. This helps justify the lower limit (conditions are different from the daytime). Probably an even better justification is the presence of nocturnal animals such as deer. This is of particular concern on small rural non-interstates, especially the rural two-laners. (This is another form of a change in conditions). The day/night speed limits are more relevant in some states than in others.

Non-Interstate Speed Limits

Four-Lane Highways

All should be set at or slightly above the 85th percentile speed or be posted as "reasonable and prudent."

Two-Lane Highways

Same as in A. Speeds, if numeric, would normally be set lower, as these roads truly are not as safe as four-lane highways (especially divided four-laners).