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Comment by ceejayoz | Hacker News Reader

They're on Waze five minutes later.

Good. If it's actually important that people drive slower in that area, everybody knowing there are speed cameras will have that effect.

If everyone guns it right after passing the camera, you've potentially made things more dangerous.

Aircraft allow for a "you could get caught at any time" deterrent that cameras can't unless you put them literally everywhere.

They still increase the safety by limiting the speed in for example an exposed intersection.

On the other hand you can go the average speed route instead.

https://en.wikipedia.org/wiki/Speed_limit_enforcement#Averag...

This is such an insane take.

The speed limit is for everywhere for safety. They faster people go the more dangerous it is.

Actually, people tend to drive at the speed that is safe, and traffic engineers set the limit at about the 85th percentile of the observed speed. Maximum limits on safe roads are usually lower than the observed speed, and so serve no purpose from a safety perspective.

Traffic calming techniques like narrower lane widths and widths are shown to be more effective than police enforcement. The “downside” of these methods are that they’re actually effective at controlling speed, and thus are a revenue loss.

Not the person you replied to, but I really feel like enforcement must be a pretty substantial part of what stops people from speeding and driving recklessly, given that traffic enforcement has been de-emphasized since the start of the pandemic and the number of road fatalities has gone up more than 7 percent, even though the actual number of miles driven has gone down.

https://www.nhtsa.gov/press-releases/2020-fatality-data-show...

If people drive at whatever speed they think is safe, then why would the aggregate number of people dying on roadways ever go up when miles driven by the same population goes down? Here are the possibilities:

1. Driving has become more risky due to external, uncontrollable factors, like weather or road changes that motorists can't account for or

2. People are modifying their behavior.

Why would they modify their behavior? The roads haven't changed. The speed limits haven't changed. What has changed? More people are dead because of extreme speed and reckless driving on roadways, which kind of suggests that traffic enforcement did at least prevent some of those deaths.

You need to stop equating speeding with driving recklessly.

Going 70-80 on a limited access highway when conditions permit is not reckless. Weaving through traffic at 20+ the prevailing speed with no margin for error is. A number on a sign does squat to effect either group.

I'm not sure there's enough information to draw such a conclusion. For example, due to changes brought on by the pandemic, the makeup of vehicles, drivers, and reasons for driving may have been significantly different.

One interesting point from your link was a significant increase in drivers involved in fatal crashes testing positive for drugs including cannabis and alcohol, but especially opioids. It would take real research to quantify the relative effects of each of:

1. Increased speeding due to reduced enforcement

2. Increased DUI due to reduced enforcement

3. Increased DUI due to pandemic-related drug use

Also, is there actually any evidence of reduced traffic enforcement? Or are people just assuming this?

Except the road conditions totally changed. At the beginning of the pandemic, you had hardly any traffic anywhere. No more were people being slowed down to 25mph on the freeway by a traffic jam. You could easily cruise 60mph into the city for a long time. Suddenly, a morning wreck meant someone crashed at 60 instead of 25.

> people tend to drive at the speed that is safe,

*at the speed they believe is safe. Most people also highly overestimate their driving skill.

When you start saying that everybody else is wrong on issues that are broadly defined by social consensus (e.g. what's a safe speed for this road, what's appropriate attire for the office, etc, etc) you're basically saying everyone is wrong except you but with extra steps.

Social consensus can be and often is wrong. Counterintuitive results like the Birthday Problem are widespread, people are shit at statistics and risk evaluation, etc.

> Actually, people tend to drive at the speed that is safe,

That not remotely true in any part of the world I've visited so far.

> The speed limit is for everywhere for safety.

Absolutely not. Speed limits that don't fit the roads they're on are not a safety measure. Outside of really blatant speeders, it's the road design that needs to make things safe or not and do the bulk of the work in guiding people to a reasonable speed.

But even separate from that issue, tons of speed limits are set for reasons like "people complained about noise, probably unreasonably" or "we want to make money off tricking drivers".

The US national speed limit was imposed as a fuel economy measure not a safety measure.

Did states not have their own speed limits prior to that? Do they not set speed limits on state or county roads today?

If speed limits are about safety, when the states set theirs and the feds over-rode them, which one was used flawed safety data (or was it “both”)?

The cameras are more effective if people have to expect them everywhere, because then they will (hopefully) stick to the speed limit everywhere.

Looking at you:

- Crotch rockets (driven by dudes in jorts and a t-shirt flapping in the wind)

- Dodge chargers w/ aftermarket exhausts

- BMWs with iridescent vehicle wraps

- Lifted pickup trucks with massively oversized tires

This reads like a Reddit comment.

So? Wouldn’t people that know the cameras are there drive slower than the people that don’t? From a public safety point of view, known cameras are more effective at limiting speed than unknown ones.

Reducing lane width is also shown to be a very effective speed control methodology, that does not require police enforcement.[0]

Or are you concerned about a loss of local and state revenue? Seriously, the use of police for revenue generation, rather than public safety is an open secret among police and local governments.[1][2][3]

[0] https://nacto.org/publication/urban-street-design-guide/stre...

[1] https://harvardlawreview.org/2015/04/policing-and-profit/

[2] https://www.policechiefmagazine.org/generating-new-revenue-s...

[3] https://www.theatlantic.com/national/archive/2014/12/the-ben...

That’s simple. Just do one camera at the beginning, one at the end and you can get average speed by simple math. While it allows you to go above the speed limit, you also have to slow down to “lose” that earned time so at the end it averages back to speed limit. Go ahead and advertise this speed trap well because the more people understand how this works the better.

You can make these cameras so dense that there is very little opportunity for speeding in between two cameras.

No need for so many cameras. You only need two :-)

https://en.wikipedia.org/wiki/SPECS_(speed_camera)#Similar_s...

https://en.wikipedia.org/wiki/Speed_limit_enforcement#Averag...

(Sorry for the nerdy nitpick)

flashback to Calc 101 and the Mean Value Theorem!

This is essentially the way it works in Switzerland. On motorways there are speed cameras every few kilometers: even with an app to warn you, it’s not worth trying to speed between cameras.

Oh man I got so many speeding tickets in Switzerland (like 5 in two years). They were all super minor like $50 or something?

I heard it does not apply to all cantons, the Italian ones speeding is more OK.

All that being said I really dislike the US system where you can pass a police car driving 75 on the 101 and he doesn't care. There has to be some enforcement of the rules.

> All that being said I really dislike the US system where you can pass a police car driving 75 on the 101 and he doesn't care. There has to be some enforcement of the rules.

The US system is a probable cause generator.

Or revenue, or both.

When you travel in a country where limits are harshly enforced, driving is wayyy more relaxing because of the reduction in speed variation (most people travelling at the stated limit) and no crazy overtaking manoeuvres (idiots don’t just harm themselves). That said, I’m not a fan of draconian speed limits.

$50 will be for a couple of km/h over the limit (after the 5 km/h "standard" deduction). At 20 km/h, it's CHF250; above that you're getting in front of a judge, will lose your driving license for a while and face thousands in fine and administrative fees.

Not sure about the 101 but most places won’t pull you over unless you’re going 10+ over. They did a super speeder law in my state where 85+ on any road or 20+ over gives you a much harsher penalty. The state patrol will sometimes sit and wait for the super speeders and let the 15+ people pass.

I'm a staunch privacy advocate, but we have thousands of people in my state dying a year from automobile accidents. (On par with gun deaths, a figure which includes 60+% suicides.)

I'm not sure I'd fight it if we lined the entire interstate highway system with plate detectors.

If your average speed is above a reasonable limit (80mph on low density straightaways?), then you receive a ticket at a rate multiplied by the duration of infraction.

Where there’s a lot of speeding to catch is low density straightaways marked 35.

Norway and Finland fines proportional to your yearly salary. Of course there are some problems with that, but in general I like that system more.

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