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by 4ndr3vv 1990 days ago
Speed limits have no minimum because driving on a road is situational; bad weather, unfamiliarity with the road, new driver, bad driver, personal safety limits, discrepancy in speedometers, and etc.

How would you go about policing this? If there is traffic, everyone is driving under the minimum!

3 comments

Most states have a blanket law that 10/15/20 below the speed limit constitutes obstructing traffic and is usually a ticketable offense.

In the digital age with sensors and data so cheap there's also no reason we can't set speed limits based on the Xth percentile everywhere with an automatic annual adjustment.

> In the digital age with sensors and data so cheap there's also no reason we can't set speed limits based on the Xth percentile everywhere with an automatic annual adjustment.

People tend to have an aversion to automation applied to law enforcement. See the criticism of red light cameras in the US.

I'm advocating for automating the rules, not the enforcement. In most places speed limits would probably rise. My understanding is that some traffic light timings are already automated in this manner.
After rereading your comment I see where I misread, my apologies.
By definition, x percent of the people are below the xth percentile. That’s not a sane way to set limits
That sounds like a pretty sane way to set a limit that by definition should not be exceeded.

It's also the way civil engineers recommend speed limits be set. I think the current number they use is 85th percentile.

Yes, California for example:

> The 85th percentile speed is the single most influential indicator of what is safe and reasonable, and it is used to determine the speed limit by rounding to the nearest 5 mph increment, and posting the speed limit at that speed. If there are sufficient conditions not readily apparent to the driver, as determined by a registered engineer, the posted speed limit can be lowered by 5 mph, and such a decision must be clearly documented in the E&TS.

https://dot.ca.gov/programs/safety-programs/setting-speed-li...

Ya, let’s implement speed limits based upon an known organizational issue that can result in catastrophic failure. https://en.m.wikipedia.org/wiki/Normalization_of_deviance
There are posted speed minimums on the tollways here in Chicago. You can't go below 45 in freeflowing traffic.
Explain that to all the people trying to merge at 35.
I have no problem with semi trucks, overloaded scrap haulers, genuine shitboxes that can't floor it without something slipping and whatnot merging at low speeds. Everyone else has no excuse.
Those vehicles shouldn't be allowed on freeways in the first place. They can use surface streets.
Stateside, many interstates have minimum speeds listed.