Well, I've been in the Middle East for over a decade now, and yes, the driving does tend to get a little bit worse during Ramadan (to be fair, it's bad all the time). And things do tend to get a bit quieter (no different than summer or the Christmas season home really), but I wouldn't hesitate to take a cab or go to a doctor. 
First off, you're allowed to break your fast if you think you might hurt yourself or others, and generally people doing jobs like that will tailor their hours so they aren't that affected.
God I wish it was 28degrees! That's positively chilly! It's 42 Degrees in the shade here today, and funnily enough no ones complaining about no water. :/