[jerf]

The "real" solution is to retrain society from top to bottom to break the conflation between what a law is and the outcome a law is intended to produce. As that phrasing implies, I don't think this is going to be an easy process.

The purpose of a speed limit is not to make people not go more than 55 miles per hour. The purpose of a speed limit is to make driving safe, and particularly to make driving safe for society, even moreso than for the individual. If everybody is driving at 65 in the 55 zone, but everybody is safe, the higher purpose of the law is being met, and citations for speeding are just punitive for no gain. When conditions make 55 unsafe, people need to slow down enough to be safe, regardless of what the local speed limit is.

Because we've never been able to rigidly enforce laws, it was very easy to conflate the two concepts. Now we are starting to develop some tech that does let us rigidly enforce laws. The solution is, don't do that. The laws we have on the books today were not designed for rigid enforcement. They were designed to be tools for creating public safety that could be used by the legal system, they are not themselves the specification of public safety. No such specification can really be created, and people are going to have to learn that.

Hopefully we learn that before we really box ourselves in with even better tech. Either way we do seem very determined to learn this the hard way.

This idea has applications to all sorts of modern day issues popular on HN; copyright law isn't really to prevent you from sharing a copy of a song with a friend, it's to prevent massive pirating enterprises that impact the market. Patent law isn't intended to provide mechanisms to sue end-user consumers of scanners that violate patents, it's intended to protect innovators from having their ideas taken without compensation by large engineering firms. Regulations in general are intended to produce certain results, usually some sort of social safety, they are not intended to becomes gods in and of themselves. But the actions of pretty much everybody in the system from top to bottom proves this idea is poorly understood.

[tomkarlo]

The solution isn't "lossy" enforcement, at least in the case of speed limits. It's to revise the speed limit to a higher, more realistic figure and then enforce that limit as rigorously as practical. This is what the UK and other countries are doing with average speed cameras.

It's been shown that in some cases US speed limits make roads less safe and are lower than the speed limits recommended by the engineers who designed the roadway.

"The design speed for the project was 110 km/h (68 mph). The design speed is like a warranty: nothing in the road design requires a driver to go slower than 68 mph, not even on a wet road at night (the design conditions).

The average speed is not far from the design speed. The 85th percentile speed, which is supposed to be used for setting speed limits, is around 75 mph. A little over by my measurement, which found 1% compliance with the speed limit."

http://marginalrevolution.com/marginalrevolution/2011/09/be-...

Having speed limits where a large percentage of drivers regularly violate them teaches people to break the law casually. (Similarly, COPPA basically teaches kids to lie about their age online.)

[jerf]

"Having speed limits where a large percentage of drivers regularly violate them teaches people to break the law casually. (Similarly, COPPA basically teaches kids to lie about their age online.)"

I'd suggest that there's also a widespread lack of understanding that there's a difference between having a law, enforcing a law, and potentially even having the capability of enforcing the law. It's part of the reason why "law" isn't the answer to every societal problem.

[krichman]

> It's part of the reason why "law" isn't the answer to every societal problem.

I sure wish more people like you had stronger control over the legislative process.

[Vivtek]

You appear to be suffering from the notion that there is a single defined value at which the speed limit will be optimum at all times.

But I entirely agree with your larger point that violation of arbitrary speed limits because of obvious engineering considerations does train people to break the law casually.

[tomkarlo]

The quote I posted explicitly points out that the speed limit is based on worst-case road conditions. Obviously a single-value speed limit can't be optimal in all conditions, for all drivers, in all vehicles. It has to be based on what's safe for most vehicles in most conditions, but there is a single optimal value for those constraints on a particular road.

I'd have no problem with variable speed limits on roads - I think it would make a lot of sense to have speed limit displays that change based on time of day, weather conditions, etc. But until that's practical, speed limits will be set based on worst-case, with a proviso that drivers ALSO have to exercise discretion and further reduce speed in exceptional conditions like fog or snow.

[kvb]

I don't think the data on optimal speeds is that clear cut. See another Marginal Revolution post for a summary of a study indicating that raising the limits generally would have costs outweighing the benefits: http://marginalrevolution.com/marginalrevolution/2011/12/sho....

[AnthonyMouse]

The conclusions are based on the idea that higher speeds create external costs to third parties which aren't required to be internalized by the driver, making the driver more likely to choose a higher speed than would otherwise be optimal.

Which means the conclusion is wrong. The solution is not to have a lower speed limit, it's to require the internalization of externalized costs: Impose a fuel tax that accounts for the full cost of the pollution created to society. Require drivers whose speed has caused a collision to pay higher insurance premiums. Then drivers will have to weigh the cost to others in their decisions and the identified problem goes away.

[tptacek]

Did you read the actual paper, or just Tyler Cowen's blurb? The paper is based on actual data, not just suppositions. It too might be wrong, but the arguments it makes are more compelling than anything in your comment.

[AnthonyMouse]

The "actual data" is just as problematic, because they took it from the speed limit increases in 1987 and 1996. Fast forward two or three decades and we have much safer cars, which will completely change the injury data. Meanwhile modern cars are significantly more efficient and have far better pollution control systems. On page 4 of the paper Benthem writes, "Perhaps surprisingly, the costs from pollution-induced adverse health impacts are about as large as the costs from traffic fatalities." (Which is astounding considering the number of traffic fatalities.) But now we have gasoline powered cars that produce exhaust which is cleaner than the ambient air taken into the engine in certain cities. We have fully electric cars. If your concern is pollution then you would do better with legislative efforts to get older cars off the road and eliminating their pollution entirely rather than only reducing it, which would also save you from unnecessarily slowing down newer vehicles that cause little to no impact on air quality.

[tptacek]

According to NHTSA, the sharpest decline in fatality rate / 100mm VMT preceded 1984, and since 1996 has dropped by something like 6%. What mainstream automotive advances lead you to believe that cars are so much safer that van Benthem's numbers are wildly off?

Similarly: the 1990s dominate van Bentham's numbers and correspond to the introduction of OBD-x. Cars are more efficient now, but by how much? There are hybrids on the roads, but most people don't drive them, and we won't be outlawing Volvos from 2000 any time soon.

[UVB-76]

Average speed cameras are actually quite scary. In the UK they have only been used (as far as I'm aware) to enforce temporary speed limit reductions, most typically during roadworks, then removed once the speed limit is returned to normal.

In theory they could be deployed across the motorway network with ease, and overnight force people to abide by the maximum speed limits (which a majority of people do not currently do) or face fines and points on their licence (ultimately leading to a ban)

[timthorn]

No, they're deployed as regular speed cameras too. The M25 cameras are linked to a variable speed limit system to dynamically manage traffic flow; not sure if that fits in your definition of temporary (the cameras are permanent but the threshold speed changes) but there are also many instances of fixed speed cameras both on the trunk road network (eg the A14 near Cambridge) and even in villages (eg in Nottinghamshire)

[igouy]

Distractions --

>>The purpose of a speed limit is to make driving safe...<<

"I hoped that the national 55-mile per-hour speed limit--already in force--would help reduce gasoline consumption"

http://www.presidency.ucsb.edu/ws/?pid=8017

>>When conditions make 55 unsafe, people need to slow down enough to be safe...<<

"California has a 'Basic Speed Law.' This law means that you may never drive faster than is safe for current conditions"

http://www.dmv.ca.gov/pubs/hdbk/speed_limits.htm

[jerf]

"I hoped that the national 55-mile per-hour speed limit--already in force--would help reduce gasoline consumption"

That's clearly not the current reason.

And more than just California has a law like that. I know Michigan does, I imagine most states do. It does show that somebody at some point understood the purpose. By no means am I saying all laws or bad, or that laws are bad, or even in a way that any particular law is bad; I'm saying people all to frequently conflate the letter of the law with its purpose.

[tptacek]

Higher-speed drivers use more fuel and produce more pollution. That's not a controversial argument. Whether or not it's the "current" reason for the 60-75mph speed limits we have now doesn't seem relevant. The question is, "should we raise the speed limit". If raising it increases the speed at which people drive, then raising it will increase pollution, and thus morbidity.

[orangethirty]

You are wrong about this part:

The purpose of a speed limit is not to make people not go more than 55 miles per hour. The purpose of a speed limit is to make driving safe, and particularly to make driving safe for society, even moreso than for the individual. If everybody is driving at 65 in the 55 zone, but everybody is safe, the higher purpose of the law is being met, and citations for speeding are just punitive for no gain. When conditions make 55 unsafe, people need to slow down enough to be safe, regardless of what the local speed limit is.

The 55 MPH speed limit was enforced by congress to reduce the consumption of fuel (gasoline). It has nothing to do with safety.

[schiffern]

>The 55 MPH speed limit was enforced by congress to reduce the consumption of fuel (gasoline). It has nothing to do with safety.

The second sentence doesn't follow from the first. I guarantee there were congress-critters for whom the safety justification tipped their vote.

[tptacek]

You write that like it's crazy. But the data shows that when people drive faster on average, accidents increase.

[orangethirty]

All I'm stating is that the double dime speed limit was enforced as a measure to reduce fuel consumption. Read this: http://www.history.com/this-day-in-history/nixon-signs-natio...

[krichman]

What's worse are laws that are basically enacted in reaction to some specific situation but shouldn't be applied or necessary in the general case.

Sometimes it seems like the majority of the legal code is archaic if not completely corrupt. I wish there was a way for the public to revoke laws that were ridiculous. Jury nullification? If there is a way they should be teaching it in the schools.