Hacker Read top | best | new | newcomments | leaders | about | bookmarklet login

> Opponents of speed limits often claim that the majority of people do not regularly drive faster than 130 km/h, ... If we look at the data, however, the picture is quite different.

> [graph showing 30% drive faster than 130km/h]

So the data actually confirms the 'common myth'.



sort by: page size:

> they drive the speed they feel comfortable with, regardless of the speed limit

My anecdata does not support this. When roads are not congested, I can see that most drivers accelerate from ~70+mph to ~80+mph right ofter the speed limit sign changes from 60 to 70.


> That's one possible interpretation, mine would be that people will always speed slightly above the posted limit because they know the odds of being ticketed are small

Data doesn't back you up. In places where they have raised the speed limit, the overall flow speed does not increase correspondingly.

People drive at the speed they deem safe irrespective of the speed limit.


It isn't true in the US either. A large region of the country has 130 km/h limits, and those limits are only loosely enforced. I've lived in regions of the US where 140 km/h is the typical highway driving speed.

Experience can vary widely depending where on the continent one lives. Some states do have low speed limits.


> ... Everyone around you is speeding; going slower is more dangerous

Yes those things can happen, however the car can allow the driver to go say 15 km/h faster, doesn't need to slow down at +0.01 above the limits.

Some people frequently go 30 km too fast... On 30 km roads in areas with children


The claim that the average speed at which people drive depends on the speed limit, and the claim that it does not, cannot both be correct.

>most people drive roughly 5 miles per hour over the speed limit >speed limit does in fact have a mitigating effect.

You got the causality dangerously backwards. That's not how policy works.

"The speed limit is commonly set at or below the 85th percentile operating speed (being the speed which no more than 15% of traffic exceeds),", as per [1].

Specifically, speed limits are not set by carefully measuring & modeling conditions on the road by direct application of science; there's no finely tuned measuring aparatus nor advanced math model. Instead we rely on drivers judgement aggregated over time, conditions, and locations. Granted, there are certain notable exceptions: bridges & tunnels where speed limit is also informed by structural constraints, and also fuel consumption reduction policy in cases like the 1973 speed limit.

And yes there are natural parallels to civil disobedience; in some cases limits got raised or lowered upon public pressure.

--

[1] https://en.wikipedia.org/wiki/Speed_limit#Maximum_speed_limi...


As someone driving on the Autobahn daily, the notion that even the majority of drivers drive the speed limits is laughable. Going 5-20 km/h faster is the norm.

> In England at least the speed limit is the absolute maximum speed at which you drive.

In theory this may be true but it's absolutely not in practice. It's not uncommon to see people at least 20mph over the limit on motorways. On the M4 that is practically the norm.


> majority of people believe their need to drive at 20% above any given limit

It’s almost endorsed legally afaik. We were even taught this “rule” at school

The insane speeding on tight country roads in the UK is absolutely bizarre. It’s in no way safe but everyone does it. My friends dad died on a motorcycle by riding around country roads too fast. It should really be a 30 limit, even 20 considering the visibility, but people drive at 60, even along single file roads that require you to reverse if you come across an oncoming car


> Driving at roughly the same speed as the rest of traffic is definitely much safer than driving the posted speed limit.

Who is causing the danger of driving the maximum legal speed.

Also, it's rare that all of the traffic flow is above the maximum legal speed. The ones speeding then cause the differential, which is the danger.

The fault is not with those not keeping up. But rather with those breaking the law because it's convenient.


Sure, but what % of the drivers habitually go faster than the listed speed limit? In the parts of the US I live in, the difference between that number and 100 is imperceptible, especially on the roads with speed limits on the lower end (~25 mph).

It's simply not true for the cities, people largely drive around 50 km/h if that's the limit. On the highways however going 30+ over the limit is a norm.

> Outside of cities you're limited to 100km/h (or less ofc - but 100km/h is the maximum you'll get if we ignore rare cases with 4+ lane roads and a solid barrier in the middle 120km/h

That's not quite correct. The speed limit is generally 100 km/h outside of cities, except when there are either two lanes (or more) per direction and a line between the two different directions or if there are less than two lanes per direction, but there is a sold barrier between them. In those cases there is no speed limit, just like on the Autobahn.


> In the UK, the motorways have a speed limit of 70mph, and most people actually do it

Are you kidding? Try doing 70mph in the third lane of a non-busy motorway and see how long it takes someone too be dangerously close behind you.


> In the UK, the motorways have a speed limit of 70mph, and most people actually do it

Are you kidding? Try doing 70mph in the third lane of a non-busy motorway and see how long it takes someone too be dangerously close behind you.


> In 2020, under free-flowing traffic conditions, 56% of cars exceeded the speed limit on 30mph roads compared to 53% on motorways and 12% on national speed limit single carriageway roads.

> In fact, only about 70 percent of it is truly derestricted, while the rest of the Autobahn has a speed limit of 100 kph (62 mph).

That's wrong, speed limits vary between 80, 100, 120 and 130 km/h on the restricted sections. 120 and 130 km/h being more common.


Do you have any citations for your claim that "people driving 15MPH under the limit (because ... their speedometer is inaccurate)" is "very common?"

Did you read the link I posted? Theres lots of empirical data out there that says that drivers drive the same speed on a road, regardless of the posted limit. That speed is based on their judgment of the road - sight lines, shoulder width, sharpness of curves, etc.
next

Legal | privacy