In Google Maps it is very simple to change your vehicle. Simply select the blue circle with the white triangle and you will see three three options (red, green, and yellow vehicles).Also, if you would like to add a report, simply select the circle with a plus on the right-hand side. There you will see options to add a report for the following: crash, speed trap, slowdown, construction, lane closure, stalled vehicle, and object on road.
Embedded below is a 41 second YouTube tutorial.
Take care, Brad