The geocoding web service running on AGRC's 9.3 ArcGIS Server instance (dagrc.utah.gov) returns geographic coordinates for street addresses and zone (zipcode or city) submissions. Coordinates are returned in both Latitude/Longitude and UTM reference systems.
After first creating a username athttp://mapserv.utah.gov, the webservice can be accessed at:
This same web service now allows for 'route and milepost' style address location. Users submit the milepost location as the address parameter and the route as the zone parameter.
All web services are meant to be accesed by web and other applications programatically (behind the scenes). However, many web services have a test page to demonstrate the functionality. Here is a snap shot of a route and milepost submission to the dagrc.utah.gov geocoding web service via its test page:
This request returns the following XML reponse containing the coordinate locations which can easily be parsed out of the XML and used by the calling application:
The physical location of mileposts is always based on the route's positive (west or north-bound) direction.
For some divided state and US highways, a negative direction route exists for the portion of the route that is defined as divided by UDOT. Locations along these routes can be found by using a N after the route number (ex. 10.544, 201N returns an eastbound location along highway 201)
For Interstate highways only, using an 'N' parameter does not return the mileposted location. Instead it returns the location corresponding to the accumulated distance in the negative direction of travel. For example, if 5.222 and 15N are submitted, the location returned will be 5.222 miles south of the Utah-Idaho border on I-15 southbound. This is how UDOT has defined its linear referencing system and their reasoning is they can inventory features easier if they measure distances while driving with traffic. If you want a more traditional mileposted location along an interstate, the route number can be submitted with an X (ex. 5.222 and 15X returns the location along southbound I-15 that is approximately 5.222 miles north of the Utah-Arizona border where the 0 milepost is found).
The GIS data layer used for this web service is: SGID93.TRANSPORTATION.UDOTRoutes_CalibratedEP and is based on route end point milepost calibration only.
The dagrc.utah.gov domain is technically a development URL. In the coming months, this URL will be subsumed into mapserv.utah.gov. Prior to this happening registered users at mapserv.utah.gov will receive notification via email of the expected date and nature of the changes.
If a need is demonstrated, AGRC plans to implement a 'reverse' route/milepost web service that, given an x-y coordinate pair, will return the closest route and milepost measure value within a specified search tolerance.
