It's not a terribly hard job actually. I worked for a startup in 2004 that was doing this with haulage companies. We had 8000 data points moving around the UK coming in via GPRS and 3rd parties, traffic information aggregated and routing and mapping data, pick up corridors and event data.

It was (bar the web front end) a relatively modest sub-30kloc chunk of C++.

Now the scale is different but in 10 years, the problem isn't necessarily much more complicated, just larger.

In fact I think a derivative of it now runs some of Yodel's operations.