The utility model provides an investigation instrument for vehicle running tracks. The investigation instrument for the vehicle running tracks comprises several laser range finders, a one-chip microcomputer and a computer, wherein, the output terminals of the laser range finders are connected with the input terminal of the one-chip microcomputer, the output terminal of the one-chip microcomputer is connected with the input terminal of the computer through a wireless transmission module, and the laser range finders are arranged at highway interchange entrances and exits and guard bars at one side of a deceleration lane. The investigation instrument for the vehicle running tracks is used for the research of vehicle driving conditions at the highway interchange entrances and exits, and the investigation instrument for the vehicle running tracks is advantaged by being accurate in measurement, easy to implement, low in cost and the like.