I have discussed how ArcGIS Online’s routing service supports optimized routing for North America and Europe, and investigated a classroom example at the city level. Now let’s investigate an example at a regional scale. Present the following scenario to the students: The Geo-Trucking Corporation, which delivers handheld mobile devices for field collection, has hired them to route a truck each week from Boston to Boise, and return, with intermediate stops in Birmingham Alabama and Fort Smith Arkansas.

Access ArcMap 9.3.1, turn on the StreetMap toolbar, and select “Find Route using online route services” . Select the North America routing service. Add a USA cities layer, select Boston, Birmingham, Fort Smith, and Boise, and add these as stops along your route. Select the shortest route on the Options tab, and use highways. Save your route and stops to shapefiles, add them to the map, and symbolize as arrows.

Repeat the process by selecting the quickest route rather than the shortest route. Is there any difference? Why? The map does show a difference, but only at larger scales. The shortest route occasionally sends your truck over state highways instead of interstate highways. In Arkansas, your truck driver will be traveling on State Highway 22 instead of I-40 from Russellville to Fort Smith.

To empirically discover the difference between shortest vs. quickest, I edited the tables, populating the distance and time fields with the data that the routing tool combined into a description field. Summarizing yielded 5,999 miles and 98 hours for the shortest route, versus 6,016 miles and 93.9 hours for the quickest route. Both routes could indeed be done in a week; the quickest route adds 17 miles but cuts over 4 hours of travel. Is there any difference if you select “local roads” over “highways?” What factors, such as rest stops or traffic, might delay the total time required for your shipment?

Through creating and comparing routes, these activities encourage students to think spatially and investigate real-world problems. 10-4, good buddy!

-Joseph Kerski, Education Manager, ESRI.