"A "business district" is that portion of a highway and the
property contiguous thereto (a) upon one side of which highway, for a
distance of 600 feet, 50 percent or more of the contiguous property
fronting thereon is occupied by buildings in use for business, or (b)
upon both sides of which highway, collectively, for a distance of
300 feet, 50 percent or more of the contiguous property fronting
thereon is so occupied. A business district may be longer than the
distances specified in this section if the above ratio of buildings
in use for business to the length of the highway exists."

The other thing is that in order for radar enforcement to occur, an Engineering and Traffic Survey must be conducted, per the anti-speed trap law, CVC 40802. The only exception is for "local streets", which are defined more narrowly than above. Otherwise, the only mechanism of enforcement is pacing or visual observation, which is more prone to error.

The anti-speed trap law is a good thing. It prevents little corrupt towns like West Covina back in the early part of this century, or more recently new Rome, Ohio, from using commuters and visitors as revenue generators. (I, and transportation expert Tom Rubin, discuss the anti-speed trap law in more detail here: http://la.streetsblog.org/2008/08/20/explanation-of-rising-speed-limits-the-public-votes-with-the-gas-pedal/ ) If you want to lower travel speed, you need to lower design speed through traffic calming, not through the posting of arbitrary signs.

I guess you're objecting to the language that the "fastest drivers will be setting the speed limit" [...] To me, cars that are in the top fifteen percent, if they're breaking the speed limit are the "fastest and most dangerous drivers," and that's the point I was trying to make.

Yes, those are the fastest and most dangerous drivers - but they're not the ones setting the speed limit.

If the slowest 85% of the traffic - the slower and less dangerous drivers - are all doing less than 38 mph, that's what sets the speed limit to 35 (or, optionally, 30). How fast the fastest 15% are going isn't a factor.

They could all be doing 38 mph - or they could be doing 45, or 55, or 85 - it doesn't matter. No matter how fast the top 15% goes, the speed limit is set by the speed of the botton 85%.

And I don't think that's "splitting hairs." The fastest drivers aren't the ones setting the limit.

As in your "pedestrian corridor" example, it doesn't matter how many of the fastest 15% "race by at 50" - the limit can still be set at 35 mph if the slowest 85% of the traffic is doing 42 mph or less.

And bear in mind that this rule only applies to "non-statutory" speed limits. All jurisdictions have statutory authority to set the speed limit as low as 25 mph in any "business or residential distict" (except on state highways), with no engineering survey whatsoever. (See CVC Sec. 22352, "Prima Facie Speed Limits".)

Since almost all "pedestrian corridors" are either business or residential districts, this rule really isn't an issue in terms of pedestrian safety (except possibly on state highways).

(And any state highway where more than 15% of the traffic is going 43 mph or faster probably does need to have a speed limit higher than 35 - even if there are pedestrians in the area.)

This just isn't the dire threat to pedestrian and cyclist safety you're trying to make it out to be, IMO.

I rechecked the document and I posted and you are correct. Reading it today, I'm not sure how I got the impression that the traffic engineers had to round up; but I've corrected the text and used the "crossout" function to that anyone reading the article will know why you were correcting me in the bottom. I regret the error.

That being said, I think you're splitting hairs with the distinction between "top fifteen percent" and "bottom 85 percent." I guess you're objecting to the language that the "fastest drivers will be setting the speed limit," because you read that as me saying the cars at the very top, like the 1% of fastest drivers, are setting the limit. To me, cars that are in the top fifteen percent, if they're breaking the speed limit are the "fastest and most dangerous drivers," and that's the point I was trying to make.

Last, the CVC does allow for engineers to take into account bike/ped and other issues. That is what allows the optional 5 mile per hour reduction that local DOT's can take. It does not allow municipalities to say things such as "this is a high pedestrian corridor, we need to keep the speed limit at 35 mph" even if cars race past it at 50 mph.

Ultimately, I think Ubrayj is correct. What we really need is better designed streets and the speed limits will follow that. However, that being said the CVC and state law treat all roads the same and that leads to dangerous streets in L.A. and other cities that have wildly different circumstances than roads in smaller rural communities.

It would be ten miles above. It's not the closest "5 mph" but automatically the next highest mph.

No, that's not what the rule says.

It says:

******
When a speed limit is to be posted, it shall be established at the nearest 10km/h (5mph) increment of the 85th percentile speed of free-flowing traffic, except as shown in the Option below [emphasis added]
******

...and it gives specific examples:

******
An example of the application of this speed limit criteria is as follows:

* If the 85th percentile speed in speed survey was 60 km/h (37 mph), then the speed limit would be posted at 35 mph or optionally reduced to 30 mph. However,

* If the 85th percentile speed in speed survey was 61 km/h (38 mph), then the speed limit would be posted at 40 mph or optionally reduced to 35 mph.
******

Further, Armen is correct. The behavior of the fastest 15% of drivers is irrelevant. It doesn't matter how fast they go. What matters is how fast the slowest 85% go.

So if 85% of the drivers are doing 37 mph or less, the limit can be set to 35 mph, or optionally, to 30 mph if an Engineering & Traffic Survey justifies the lower limit.

And, contrary to the second paragraph of your post, where you say:

Those people walking or biking aren't considered at all in these engineering surveys, mistakingly referred to as science by car-loving politicians.

...the definition of Engineering and Traffic Survey in CVC 627 specifically says:

******
When conducting an engineering and traffic survey, local authorities [...] may consider all of the following:

(1) Residential density [...]

(2) Pedestrian and bicyclist safety.
******

So you're wrong on three counts here: it's the nearest 5mph interval to the 85th percentile, not "automatically the next highest"; how fast the top 15% of speeders are going is utterly irrelevant, not what determines the limit; and local authorities can and do consider pedestrian and cyclist safety in the Engineering & Traffic Surveys that are used used to justify the optional 5 mph reduction.

It would be ten miles above. It's not the closest "5 mph" but automatically the next highest mph.

No, that's not what the rule says.

It says:

>>>>
When a speed limit is to be posted, it shall be established at the nearest 10km/h (5mph) increment of the 85th percentile speed of free-flowing traffic, except as shown in the Option below [emphasis added]
<<<>>>
An example of the application of this speed limit criteria is as follows:

* If the 85th percentile speed in speed survey was 60 km/h (37 mph), then the speed limit would be posted at 35 mph or optionally reduced to 30 mph. However,

* If the 85th percentile speed in speed survey was 61 km/h (38 mph), then the speed limit would be posted at 40 mph or optionally reduced to 35 mph.
<<<<

Further, Armen is correct. The behavior of the fastest 15% of drivers is irrelevant. It doesn't matter how fast they go. What matters is how fast the slowest 85% go.

So if 85% of the drivers are doing 37 mph or less, the limit can be set to 35 mph, or optionally, to 30 mph if an Engineering & Traffic Survey justifies the lower limit.

And, contrary to the second paragraph of your post, where you say:

Those people walking or biking aren't considered at all in these engineering surveys, mistakingly referred to as science by car-loving politicians.

...the definition of Engineering and Traffic Survey in CVC 627 specifically says:

>>>>
When conducting an engineering and traffic survey, local authorities [...] may consider all of the following:

(1) Residential density [...]

(2) Pedestrian and bicyclist safety.
<<<<

So you're wrong on three counts here: it's the nearest 5mph interval to the 85th percentile, not "automatically the next highest"; how fast the top 15% of speeders are going is utterly irrelevant, not what determines the limit; and local authorities can and do consider pedestrian and cyclist safety in the Engineering & Traffic Surveys that are used used to justify the optional 5 mph reduction.

The speed limit gets set at whatever limit captures the behavior of 85% of motorists, not the other 15%. If 85% of drivers are driving no more than 35mph on a road, the limit will be 35mph.

If no more than 15% of drivers on a road are driving 50mph, with let's say the rest coming in at 47 or under, then the limit would be 45mph.

Booting responsibility for this up to the State, and keeping pressure off of roadway engineering and planning at the local level, is not a recipe for successful protection of pedestrians and other slower moving modes in the right-of-way.

Our roads are designed for speeding, and voila!, we get speeding.

Krekorian bill was far to extreme in that it gave no regard to studies of any kind and tyranny of the minority - local authorities when corrupt...