This seems like a nice suggestion but I see this looking fairly messy on populated roads. If anything, I'd like the icons to be a triangle so you are able to see which direction they are heading, like @Niuro_BG has stated in their comment. Also, am not developer but I can see this clogging up the system as it needs to work out which players are in cars and which trucks have trailers or not, but just having it as a simple triangle would be much more simpler and way more useful. However, I don't feel this is a huge priority at the moment because you should always check your surrounds and your mirrors if a player is approaching from either direction. As I said previously; this does sound like a nice suggestion but I'd just prefer it to be a triangle that way I know for sure which way the player is heading, however, if in populated areas (e.g. Duisburg) I will obviously still be checking my mirrors and surroundings as it would get pretty hard telling where they are heading on the GPS due to there being so many players in that area.