The flyover and the roundabouts
The Chiswick flyover has no hard shoulder and nowhere safe to stand. A vehicle stopped on it is a serious hazard, and it is one of the few places in West London where the honest advice is to get away from the car entirely and call 999 before you think about recovery.
The Hogarth roundabout and the Chiswick roundabout beneath the flyover are both heavy merging environments where low-speed shunts are frequent. Those are usually straightforward recoveries once the vehicle is off the junction itself.
