Just like the dropships are not meant to kill people by squishing them (remember when that use to be a problem?), LAVs are not meant to kill people by hitting them; that's what the turret is for. Roadkill should not be a legitimate playstyle, it diminishes the value of the turret and the need for teamwork with the gunner, and its one-hit-kill and incredibly easy nature makes it overpowered, especially when you can do it for free.

The roadkill issue won't go away if LAVs get an HP nerf, it was always present. Nerfing HP will just turn them into fast moving glass cannons one-hit-killing everyone, but just more easily destroyed; won't do much since more free ones can be called in.

Removing free LAVs would also be a bad idea. Vehicles are just a part of this game as infantry, and its only fair that they get at least one starter fit since infantry has 4.

In the past I would have suggested something like making the LAV receive some damage from the impact (they get impact damage from hitting walls and rocks, but not heavily armored and shielded mercs), but I don't think all that is necessary.

The easiest solution would just be to nerf the collision damage LAVs inflict on infantry. Make full speed collision do only 150 damage to infantry.

Some people will likely say something dumb like "stay out of the road" or "watch both ways before crossing", but that's really just like saying "stay indoors" or "always look above your head" a few builds ago when dropships were effortlessly crushing enemies. The fact that you can do something to avoid being killed by something OP doesn't make it any less OP.