This is a great idea. I'm a heavy vehicle driver, and length is also a feature that would help me very much. Currently, Waze suggest a U-turn over a 5m island/median, but with 22 meters vehicles, those U-turns always cause traffic problems. I have to turn around, driving around an entire street block. Some roads have vehicle length restrictions.
Weight will be really great, because I weigh sometimes 56 metric tons.
Height is important, because our legal height is 4.2 meter, which means overhead roadsigns is slightly higher. I very often find those roadsigns and bridges damaged. Some bridges are irregularly low (eg. 3.5 meter) and some roads have height restrictions to eliminate heavy vehicle traffic.
Width is not really that important in South Africa, but usually low or almost no traffic on street segments, tends to be quite narrow, where length is a real problem.