You can access this tool from the following:
Start Station assigns stationing to an element. You assign a station value and a position along the element for that station value. This tool can be used on a civil element or a plain MicroStation graphic. If this tool is never run, then the beginning stationing is assumed to be zero. If the position along the element is not at the beginning of the element, the assigned station is projected back to the beginning point of the element, so the entire element is stationed. For example if the selected position is 500 master units along the element and the assigned station is 25+00, the station at the beginning of the element is 20+00.
Many of the preferences for stationing such as decimal places, location of plus sign, etc. are controlled within the Design File Settings. (link to Design File Settings).
Use Power Selector to select the element to see edit manipulators.
Click the text to change the value of the station.
Click the arrows to move the location of this station value.
Project Explorer and Properties
Any element to which stationing is assigned reports those in Element Info. Station values can be edited as alternative to using the manipulators. Stationing can be removed by right-clicking on Stationing and select Remove Stationing.
The Assigned Location is the distance along the element to the selected point (Start Distance). The Assigned Station is the station assigned to the Start Distance point. The Begin and End Station are stationing at the beginning and end of the element.