Linear Referencing

Problem

To investigate accidents on roads in Pitt County, NC and determine the relation between road condition and accidents.

Analysis Procedures

Linear referencing (LR) is a process of linking events to a route. LR stores geographic locations of events that occur along a route (network). The overall strategy was to convert road condition and accident data to route event layers using ArcGIS software.

Data: Accident data is stored as point.  Pavement data is stored as line.

I added city and county shapefiles to ArcMap. Then I added accidents point table and using the route event layer tool created a route event point layer.  Using the same method, I created the route event layer for pavement line data. I then calculated the distance of the segment – route 30000030 for the rating of the road less than equal to 75 and greater than 75.  Finally, I created a new route event layer by intersecting accident and pavement route events.

Flowchart


Results


Application & Reflection

Problem: Linear referencing is useful for monitoring traffic accidents on I-85 that crosses through Charlotte, NC.  The Injury prevention researchers working with NC Department of Transportation wants to identify the locations at which collisions especially due to DUI occur frequently. 

Data needed: Auto collision data organized by type, ranking, and fatality can be obtained from NC DOT.  Additional data on the speed limit, pavement quality, number of lanes can also be obtained from NC DOT.

Analysis. The data will be geocoded after importing into ArcMap.  Then using Linear Referencing tool in ArcGIS 10.6.1 route locations will be identified.  Finally, the accident event and the road condition data will be used to count the number of accidents happened along the particular route