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What qualifies an intersection as "dangerous"?

darnoldy

Cyburbian
Messages
52
Points
4
Cyburbians-

Maybe its not an answerable question... or I haven't asked it right. But you folks seem to know a lot of stuff.

Is there a commonly-accepted threshold, above which one can no longer simply write off accidents as "failure to yield" or "driver inattention" and need to take a look at roadway design?

--don
 

arcplans

As Featured in "High Times"
Messages
6,352
Points
25
Cyburbians-

Maybe its not an answerable question... or I haven't asked it right. But you folks seem to know a lot of stuff.

Is there a commonly-accepted threshold, above which one can no longer simply write off accidents as "failure to yield" or "driver inattention" and need to take a look at roadway design?

--don
Many factors. Textbooks and liability would state intersections that do not meet generally accepted standards established by the USDOT / USFHWA, and in california, intersections not meeting design standards established by Caltrans and/or the jurisdiction. I never call an intersection "dangerous". It's too much lability. It's kinda like calling vehicle collisions "accidents". It assumes someone or something is at fault, when they may have been no fault at all other than God.
 

darnoldy

Cyburbian
Messages
52
Points
4
Okay...

So, I live at the intersection of two 25-mph streets, the E-W street has stop signs. In the seven months that I've been here, there have been seven collisions at this intersection, that I know of. This seems excessive to me (as a non-professional). Most have been between cars going eastbound and southbound. I think the city should explore changes to the intersection to reduce the incidence of collisions. So far, their response has been that the streets meet " design standards" and shouldn't be having any collisions.

--don
 

DVD

Cyburbian
Messages
13,151
Points
32
That's the standard answer. The bigger question, is the 7 accidents just a recent thing. Sometimes you get a run of idiots, but they have now learned to stop at the stop sign. Does the intersection have high accident counts compared to others in the city? Is 7 considered normal for the city? Is the accident just a fender bender or is injury/death involved? Other considerations: is there a lot of cut through traffic for some reason? Is the stop sign obscured somehow? Why are people not stopping like they should? Maybe having the police hang out a little and up the tickets would help? Are the oncoming cars visible?

The sad answer, you live on local neighborhood streets. Beyond a stop sign there isn't much that can be done without spending a lot of city resources on what amounts to a small problem. Sorry, it sounds mean, but consider the big picture of the city. Local streets are not often a big picture problem. If you have a good community association of some kind you might be able to work with the city to raise money for some traffic calming devices if speed is a problem. It involves some fundraising, and please think beyond speed bumps. They are ugly and not as effective as other methods like curb bump outs. The most you can expect the city to do would be put up more stop signs which doesn't do much if people are already running them.
 

arcplans

As Featured in "High Times"
Messages
6,352
Points
25
Okay...

So, I live at the intersection of two 25-mph streets, the E-W street has stop signs. In the seven months that I've been here, there have been seven collisions at this intersection, that I know of. This seems excessive to me (as a non-professional). Most have been between cars going eastbound and southbound. I think the city should explore changes to the intersection to reduce the incidence of collisions. So far, their response has been that the streets meet " design standards" and shouldn't be having any collisions.

--don
A good place to start is a SWITRS report. You can obtain that from the CHP and that should go back a few years. Sounds like a residential street merging onto a collector / arterial, and unfortuantely driver error probably is the main cause of collisions (turning movements) versus the actual intersection design.
 

Coragus

Cyburbian
Messages
1,292
Points
23
We have an intersection that had five severe crashes in five years, including one fatality. That qualified as dangerous and the state DOT is redesigning the intersection.
 

darnoldy

Cyburbian
Messages
52
Points
4
Thank you, all for your responses.

@dvdneal--those are all really good questions. It was, I think, mostly the unresponsiveness and incuriosity of the city staff that bothered me...

I have had a response to my follow-up email (that may be in part due to the fact that I cc'd the city mgr, city attorney, and mayor in that one).

They sent me a new report that still doesn't show any of the 7 accidents since last September--but I suspect that is just latency in the data.

They are doing a "stop sign survey"-- they laid out the cables for it on Friday. We'll see what happens.

I suspect that this is a sight-line issue, and $5 of red paint applied to 25' of curb will fix it. We'll see if the come to a similar conclusion.

--don
 

glutton

Cyburbian
Messages
393
Points
11
Thank you, all for your responses.

They sent me a new report that still doesn't show any of the 7 accidents since last September--but I suspect that is just latency in the data.

I suspect that this is a sight-line issue, and $5 of red paint applied to 25' of curb will fix it. We'll see if the come to a similar conclusion.

--don
State DOT crash reports have at least a 1 year lag time. 2018 data should be releasing around now. Not sure what kind of municipality you live in, but do you have a bike-ped advocacy group? Where I live, the bike-ped advocacy group does a lot of work every other year or so to data crunch crash history and analyze it the way a consultant might (but obviously with more of an advocacy lens). The way I've seen improvements happen in local neighborhood streets is going through the local councilperson and pushing for a few years. Also, showing up at any community budgeting forums that may happen once a year at various areas around the city. Lastly, check if your municipality has any sort of Vision Zero programming or project fund. I think the City of Seattle has some sort of pot for community/artistic crosswalks, for example, that neighborhood groups can apply to for matching funds.

But overall, as others have said, they'll prioritize areas that impact the most amount of people. Usually these aren't local streets unfortunately.
 

darnoldy

Cyburbian
Messages
52
Points
4
State DOT crash reports have at least a 1 year lag time...
I failed to post the resolution of all of this....

Based on a casual conversation I had with a community service officer of the local PD. I made a records request for all calls for service at that intersection. As it turns out, not all accident reports make it from the PD database to the traffic engineer's database--the PD had a much longer list.

It took another three weeks for the traffic engineer to get a copy of the report from the PD (I was not allowed to give him a copy of what I got). Within a few weeks after that, the intersection became a 4-way stop. Problem solved.

--don
 
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