Bruce Johnson's take on Speed Limit Related Issues

brucej@pc01.lsua.edu
Feb 26, 1995

The 85th percentile rule (better for law enforcement, too), The so-called Safety Advocates and their bag of tricks, Insurance Companies (It's time to slaughter their CASH COW), Media Bias, The Games People Play, Reading and Driving, Respect for Police and Laws, Waste of Resources, Slow Pokes, Why the NMSL Didn't work


The 85th percentile rule

better for law enforcement, too

The patrolmen whose task it is to enforce speed limits ought to be happy to have speed limits set at or just above the 85th percentile speed(unless there is a ticket quota). Assume that in one hour, one thousand cars pass a given point. Assume there is one officer to patrol it. Assume also that he can stop and write up 12 drivers per hour. If speed limit is set such that two-thirds of the motorists ignore the limit, the patrolman must either target 667 cars out of 1,000, or set his own "tolerance" to cut this down. To target anyone exceeding the posted speed, he is, at best, going to catch 1.8% of them (12/667). It's hard to call that effective enforcement. In most cases, patrolmen will set their own tolerances, but those often are unknown to motorists. The result is confusion as to what the "REAL" speed limit is. If the speed limit is set to the nearest 5-mile increment above the 85th percentile, the patrolman will be targeting less than 150 cars. That means even without a tolerance, a much greater proportion of violators will be caught. Of course, studies have shown that setting speeds according to the 85th percentile speeds minimizes accidents. This is the best reason of all to set speeds using the 85th percentile rule.

Also, states that set higher limits will find that people won't automatically drive "10 over" or "15 over." Remember, in many states, tolerances are 10 or 15 over the limit and people know they can get away with it. With higher limits, the police won't need big tolerances to get thier target group down to a manageable size. Besides, people may feel safe at 70 or 75 in a 55 or 65 zone, but there is no reason to believe they will automatically increase to 75 to 80 or 85 to 90. They didn't drive that fast before the NMSL. If there is a small increase, some of it will be because many motorists are "speed hungry." That will subside once freedom is gained. As mentioned, the fastest drivers seem to be in the states where no plans exist for change. Motorists are rebelling out of frustration.


The so-called Safety Advocates and their bag of tricks

Their most used statement is "there were fewer highway deaths in 1974 than there were in 1973, and it was all because of the 55 mph speed limit." OOPS. Did they "forget" to mention that there were many FEWER MILES driven by motorists in 1974 than in 1973? We had gas lines, threats of unavailability, not to mention prices twice that of the prior year. They concentrate on the number of deaths and not the death rate per mile(s) driven. Statistical tricks like this are used when the data do not support the argument. These tricks insult my intelligence and lead me not to trust the "safety advocates." These people have left out some other key points:

Cars are much safer today than they were in 1973. Look at an old issue of "Consumer Reports" or other magazine whose people tested cars in the early 70s. Look at the stopping distances. Now look at the stopping distances of today's cars. Hard to believe, isn't it. Before you put the magazines away, look at gas mileage. We know that, for many years, the EPA has tested fuel efficiency at 55 mph. Note that in those days, the EPA estimates were higher than the actual mileage found by the people testing the cars. This lasted until the late 80s. Look at the new cars. The mileage found on the highway by the testing group now almost always EXCEEDS the EPA estimates. The new cars cannot be compared with the old ones when talking about fuel efficiency at a particular speed. My car always gets better mileage at 70 than at 55 (31 vs. 28 mpg). Cars in the pre-NMSL days did not have computerized components in their engines--today's do.

Safety advocates forget to mention that nearly all cars on the road today have shoulder strap seat belts, whereas they were in thier infancy in 1973.

Many states now have seat belt laws. In 1973 they did not.

The safety advocates tell us more by what they do NOT say than by whet they DO say. I still don't know how they came up with that figure of 6,400 increased traffic deaths as a result of the NMSL's demise. They probably don't either.


Insurance Companies

It's time to slaughter their CASH COW

It is difficult to believe an insurance company's claim that they need more money when you know that the insurance company owns an island and throws extravagant parties for its highly paid executives. The cash cow may be sick. Insurance companies loved the NMSL more than mice do cheese. Talk about money in the bank. There's nothing like being able to add "points" to the drivers licenses of motorists who are driving at once legal safe speeds and getting ticketed for it. Wow! A huge increase in return without an increase in risk! Hey, investors, don't you wish YOU could find THAT??? It seems New Jersey just killed a cash cow in that state, making any ticket writen for 15 mph or less over the limit not reportable to insurance companies. Hope that starts a trend. Insurance companies also are well known for buying radar guns, etc... and giving them to police. Can you say "GOOD RETURN ON INVESTMENT?" I knew you could!


Media Bias

Back in December, when states started changing their speed limits, the media gave more attention to the safety advocates' doomsday cries than to the vast majority of motorists who want reasonable limits. Not good journalism. We'll get the last laugh when the advocates' predictions of highway carnage fail to materialize.


The Games People Play

Due to unreasonable speed limits, there are high tech cat-and-mouse games between police and motorists. Remember the cold war with the Soviet Union? Remember the arms race? MAD (Mutual Assured Destruction)? This is the high tech version. We buy better radar detectors, they buy better radar guns, we buy new and improved radar detectors, etc... Maybe that will decline in some states now.


Reading and Driving

Another thing an artificially low speed limit does is promote highway reading. Have you ever been in a heavily patrolled 55 mph zone and you got so bored that you picked up a book and read? Do we really want people reading on the highway? Wouldn't it be safer to have a speed limit people could tolerate? I'm enjoying the book I'm reading driving to and from work. I'd rather enjoy it somewhere else.


Respect for Police and Laws

It is impossible to respect unreasonable laws, and it also is impossible to teach our children to respect them. People generally had respect for the highway speed laws before NMSL. The only way they will again is to have reasonable laws. The police, although they only enforce the law, catch the brunt of the motorists' ire. They lose the respect of the motorist when they enforce an unreasonable law. It is hard to respect someone who penalizes you for something you know is not wrong.


Waste of Resources

Our police are a resource. Shouldn't we use them as efficiently as possible, especially when we pay their salaries? Why waste police resources on enforcing unreasonable laws? Do we really need a taxman with a badge? With a reasonable law, there would be justification for penalizing violators, and police would not have to target the majority of drivers or make tolerances (see III. A. above).


Slow Pokes

There is nothing more aggravating than a painfully slow driver on a two-lane highway who refuses to pull over and let traffic pass. When I was growing up in Oregon, there was a law whereby slow vehicles having more than 3 vehicles behind it must pull over as soon as it is safe, and let the other vehicles pass. Such laws should exist in all states. Slow pokes aggravate people and promote tailgating and unsafe passing. Of course, the other drivers should not do these things, but this increases the chance of them happening.

We pay so much attention to maximum speed limits, but minimum speed limits also are important. There should be a range of speeds. Not just 70 or less or 65 or less, etc... In some states, you see minimum posted speeds. We should see more of this. By keeping traffic in a smaller speed range, we lower the standard deviation, and, as a result, we lower accidents, ceteris paribus (everything else held constant).


Why the NMSL Didn't work

"One size fits all" may work with T-shirts, but it doesn't with speed limits. Homogeneous speed limits in a heterogeneous country did, and always will, breed contempt. Besides, it was micromanagement by the federal government. That never works well. It's like having a business headquartered in Dallas and having subsidiaries in California and Florida, and all decisions, no matter how small, are made by the home office in Dallas (like getting permission to buy postage stamps to mail a letter). Sounds silly, doesn't it? I guess it didn't to the federal government in 1973. Thanks to the NMA, that silliness is over. Let's make sure it's not repeated.


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