Reps will tell you not to hire a car it is too dangerous. We did because it was integral to our plans and we loathe coach trips. As long as you follow the rules driving in Mexico is a dream. Rough guide informs; flashing your headlights to another car means 'I am coming through' or ' I claim priority' this is the opposite to the UK where it means 'help yourself'. Turning left where there is no feeder lane necessiates you pulling over to the FAR RIGHT and waiting until both lanes are clear for you to cross over. Driving in Italy was much worse. Negotiation one way grid systems is hard so you must get directions from hotels. I drove in Playa for an hour in the rush hour and then it started to rain heavily but I was not freaked, I just could not work out how to get back to the hire company ! Mexcianx helpfully use their hazards whenever there is any minor issue so you will always be alerted. BEWARE when hiring, there are three levels of insurance and the highest, fully comp, still does not include windscreen replacement.
This is so easy. Roads are great, the only bit of rough road was halfway up between Tulum and Coba and even that was being replaced when we were there. There is very little traffic anywhere outside the towns. The Superhighway from Cancun to Merida is fantastic. It cost us about £16 Uk to go the whole distance and there were two paypoints. Towards the Merida end it becomes free anyway. HOWEVER, BEWARE, there are NO petrol stations along this so you must start with a full tank, we got to the outskirts of Merida with a red indicator and I was worried, however, there was a petrol station on the very edge of town on the other side of the road so I turned left and went back to it. I used the 'RETOURNO' which are placed all along the big roads to enable you to go back on yourself, veyr useful. We passed about 20 cars along the whole distance. We also travelled back along the non superhighway route, which we thought would be more scenic but it was not. Yes, you pass alot of interesting villages but if you are not going to stop don;t bother. it took 4 hours Playa Carmen to Merida non stop.
We drove Playa Carmen - Merida - stayed overnight in merida - then to Izamal - Chichen Itza overnight - Ek Balam - Playa Carmen.
We did not have a single road problem other than the bugs and insects hitting the windscreen which means you have to clean it and replace the water all the time. We also hit a pretty bird. Roads were flat, even and speedy due to the lack of traffic. HOWEVER, BEWARE the speed bumps. When you get to a small villages or anything bigger there are speed bumps the size of the Himalayas to mount or else there are nasty little spikey bumps. These are there for a reason and repeated all through the villages to stop people speeding through where children will play on the roads. The only problem was the DOGS they sleep right by the side of the road and practically in the middle of it in the towns and villages, I saw one dead one but otherwise managed to evade them easily because I was forced to go slow. this is the way to see real Mexico and not be stuck in touristy areas only.