Sitting in traffic and all of a sudden the ABS, ESP and BAC lights come on, with a constantly rotating message for each saying visit workshop. There is no noticable difference in the drive of the car, so I'm wondering first of all what might have caused it and secondly is it safe to drive. Any advice would be appreciated.
Brake switch has probably broken. Safe to drive except that your ABS won't work, cruise control won't engage and traction control won't cut in if your wheels start to slip. You should probably visit the workshop 
it is actually a fairly cheap job if it's just the brake switch.
it is actually a fairly cheap job if it's just the brake switch.BAS/ESP Brake Light Switch Fix
If you are comfortable using a phillips screwdriver, you can replace the brake light switch yourself and save some money.
Instructions on how to do it can be found here:
http://www.benzworld.org/forums/forums/thread-view.asp?tid=1166641&posts
You'll need a new brake light switch which can be ordered online for about 12-15 US dollars, or you can walk into a Benz dealership and buy one for about $20-$30 US dollars.
If you are comfortable using a phillips screwdriver, you can replace the brake light switch yourself and save some money.
Instructions on how to do it can be found here:
http://www.benzworld.org/forums/forums/thread-view.asp?tid=1166641&posts
You'll need a new brake light switch which can be ordered online for about 12-15 US dollars, or you can walk into a Benz dealership and buy one for about $20-$30 US dollars.
