TomTom has released Advanced Driving Attributes (ADA) for OEM partners to enable Advanced Driver Assistance systems (ADAS).

There are many features, all helpful for making cars more economical and able to be autonomous. See here;
http://automotive.tomtom.com/en/real-time-maps/adas-advanced-driver-assistance-systems

What caught my eye is how they now have data for gradient and absolute height. This lets cars know when they can coast and save energy. It is the first step towards true 3D mapping for autonomous vehicles.

Technology manufacturers are always looking to add more to their products, and 3D mapping will arrive one day – it is a certainty.