I'm a chemical engineer who has periods of very heavy travel (BWI-MEM weekly) and periods of no travel and that's largely depended upon employer and work assignment. I tend to have more travel when I'm working as a project engineer rather than a process engineer. The heaviest travel period was when I was responsible for overseeing a contract manufacturing operation.

Consulting engineers have a tendency to have a lot more travel involved especially since their projects aren't necessarily located near their offices in most cases. It also depends on how much face time the client requires.