Your question is from the area of Combinatorial Optimization. There are very many of such topics, but you should understand that any of these topics should be transformed into a discrete mathematical model, which must be solved by an Exact Algorithms or (most likely) Approximations Algorithm. If you possess the skills of discrete mathematics, then you will be ready to solve these models, otherwise you will need first to study this subject at its core.

In my humble opinion, these axes are topical, such as:

big data and transportation (distributed and scalable computing, large scale graph problem solving ), IoT and Intelligent Transportation Systems (Real Time Complex Event Processing) , autonomous vehicle (Real Time Reasoning), transport safety (algebraic specifications for embebded systems, software safety) etc.