I've been working as a Civil for 8 years now and I would recommend that, unless you are looking to do Structural Engineering, that you do NOT pursue a masters. In the "real world" that masters #1 won't be rewarded by salary (at least not comparative to the amount of time and money you'll put...
I wanted to post to this thread as well as I of course saw it 2 seconds after posting a similar question in another thread. I am 29 years old and considering the switch just now, and I worried about graduating with the PhD at around 40. I won't be able to enter a program for another 4-5 years...