As soon as you landed at Cancun airport and get around by car, you will experience the only federal highway in Yucatan - the 180D and of course you have to pay toll to use it.
If you are not in a hurry and like to see a bit more of the towns, I recommend taking the old road 180.
Do not worry ending up in the jungle by following your map telling you are on a main road. I ended up several times on such roads made of gravel or dust.
In Yucatan they also have funny markers on the side of the road, showing the entrance to somebody's home.

Driving in Yucatan is easy as there is not a lot of traffic. Even at night, it is not a real problem, as long as you are alert for topes, pedestrians on the road and vehicles without tail or broken head lights.
On the old road 180, you should always be prepared for the topes - speed bumps. Rising from the ground up to 30 centimeters, they are sometimes not visible especially at night time and if you do not break early enough, they could cause a lot of damages to your vehicle.

Mexico is known for being the last place where the Volkswagen Beetle was produced - here called Vocho. The last ones were produced in 2003, however you can still find a lot of Vochos there. Some of them are pimped Mexican style like the rental car shown here.
All around Yucatan, you can find cars which are hardly operational anymore, but they are still being driven around. Safety standards are much lower than in most countries :)