Imagine that at some point a maintenance crew went out into the field and recorded the actual mileage for this new route. The mileage might be captured every time the new route intersected another road. In this example you'll see how to recalibrate the newly created route based on this mileage information.

The newly created route should still be selected. If it is not, select it. Next, click the Editor menu and click Snapping. Turn on snapping to the end points of the features, in this example the routes_new and base_roads layers.

With the snapping environment set, you can create calibration points that are snapped to the end vertex of the features in the routes_new layer, thereby ensuring accuracy of the route measures at the calibration points. Setting the snap environment, however, is not necessary for the Calibrate Route command to work.

Click the Task dropdown arrow and click Calibrate Route Feature, then click the Calibrate Route button on the Route Editing toolbar.

The Calibrate Route dialog box will open, but it will be empty. Next you'll digitize the calibration points. With the Calibrate Route dialog box open, click the Sketch tool on the Editor toolbar.

Click along the route at the calibration locations (in this case the intersections) to create the calibration points.

The NaN values represent unknown M values.

Type the New M values for each calibration point by clicking each row in the New M column and typing the new value.

Save your edits after you've calibrated the feature.