It's not normally too bad where I live, but I've had 2 genuine near death experiences in the last week (same ride, 2 minutes apart) by people with no regard for other road users. One where a motorbike (Yamaha R1) decided to undertake a car at a roundabout, saw me on the roundabout at the last second, slammed on, ever so slightly brushed my back wheel, and sped off without even looking to see if he'd cleaned me out. 1/10th of a second earlier and it would have been a different outcome. Second was an idiot in a RS Focus who lost the back end when he floored it turning out of a junction and nearly went sideways into me.
I just treat other road users with the respect I expect in return. I don't undertake at traffic lights, I keep to the left at all times (except when turning right), I won't jump the lights or ride on the pavement to avoid stopping at lights. If I do hold traffic up for any reason, I'll always thank the driver for being patient and giving me room as they go past. If anyone does cut me up, give me insufficient room or rides me into the gutter then I just shake my head at them. It's just not worth getting angry.
Basically I just following the Highway Code. If you on the road, expect to abide by the code, and if you don't, then you don't really have much comeback if you have of cause an accident.