Brake issue

I have a 2006 aveo, something strange has happened on this car in the last month! When i go to stop at the bottom of my road ive pressed the brake pedal and it will not move, you cant push it down at all and im a pretty good size guy, It scares the by jesus out of you! Its almost like an air lock or something similar. It has only happened in this same spot twice, ive had to grab the e brake to stop, when i pull out on the highway everything is all good again, brake pedal pushes easily and brakes work good. Any ideas where to begin would be an awesome Thanks!

Slow buildup of vacuum pressure? Possible vacuum leak? I dont know. I'm grabbing at straws here. Anybody else want to get in on this?

I'd flush the complete brake system, and clutch (if manual transmission). Then I'd inspect the pads/shoes, discs/drums and calipers for defects or possible problems. If that doesn't cure it, you'd probably be looking at a bad master cylinder.

sounds like the brake booster/vacuum leak, do you have abs?

Sorry for the delay guys! I took the kids camping for memorial weekend. This does not have abs. Ive kinda thought along the booster or a vacuum leak also. Thanks for all the replies!