topic Re: Traffic Collision mapping in Transportation Questions

Traffic Collision mapping

TomMagdaleno — Wed, 20 Jul 2011 21:54:58 GMT

I was wondering what other cities/counties, etc are doing for traffic collision mapping of accidents. I have noticed their are three basic schools of thought on how to collect the data, they are:

1. Snap the accident point to the nearest intersection.

2. Have police officers take Latitude/Longitude at the point of the accident.

3. Record them as Primary Street and Distance from Cross Street.

We currently use method 3, they are entered by a police officer into an Access database. The database has fields for "at intersection" true/false, �??distance�?� from intersection in feet and �??direction�?� from intersection.
We export out a table and run an Avenue code that will place the points. If it is at the intersection a point is placed where the street centerline crosses. If it is a distance from the intersection the point is placed on the �??primary�?� street a certain distance and direction (N,E,S,W) from the intersection on the �??secondary street�?� .
I'm trying to find a modern way to do this. I am not a python expert, so I haven't had luck doing it that way. I was even thinking of designing a flex app and giving the police officers access to it to place their points. What method are you using?

Re: Traffic Collision mapping

BrianGeiger — Fri, 16 Sep 2011 15:47:54 GMT

Kansas DOT uses the third method, although I think they're trying to switch to a Lat/Long eventually.

Re: Traffic Collision mapping

TomMagdaleno — Fri, 16 Sep 2011 15:51:01 GMT

Thanks for the reply GeigerBC. What process do you use to plot the collisions? Do you do them manually or do you have some python code to accomplish the task? We have an old Avenue code that does the job, but I am trying to update it.

Re: Traffic Collision mapping

BrianGeiger — Fri, 16 Sep 2011 16:04:22 GMT

I actually ended up hand plotting them for a short 3 mile segment in Google Earth for one project. We had access to the actual crash reports to verify the locations as well.

Lately we've had better luck obtaining pre-plotted points from a client as shape files, but we've not seen the crash reports to know how accurate the points are plotted. Sorry I couldn't be more help.

Re: Traffic Collision mapping

weipan — Tue, 13 Dec 2011 21:11:37 GMT

We aren using the method 2 and method 3. If no (X,Y) or (Latitude, Longitude), just using the address locator to geo code the collision point.

I was wondering what other cities/counties, etc are doing for traffic collision mapping of accidents. I have noticed their are three basic schools of thought on how to collect the data, they are:

1. Snap the accident point to the nearest intersection.

2. Have police officers take Latitude/Longitude at the point of the accident.

3. Record them as Primary Street and Distance from Cross Street.

We currently use method 3, they are entered by a police officer into an Access database. The database has fields for "at intersection" true/false, �??distance�?� from intersection in feet and �??direction�?� from intersection.
We export out a table and run an Avenue code that will place the points. If it is at the intersection a point is placed where the street centerline crosses. If it is a distance from the intersection the point is placed on the �??primary�?� street a certain distance and direction (N,E,S,W) from the intersection on the �??secondary street�?� .
I'm trying to find a modern way to do this. I am not a python expert, so I haven't had luck doing it that way. I was even thinking of designing a flex app and giving the police officers access to it to place their points. What method are you using?