Agree with Stokecity here. On an M-way bridge at twilight is going to often arouse suspicion. I do some work for lorry mags and there are always reports of mindless idiots throwing stuff m-way bridges at trucks and cars - several fatalities a year in the commercial driver sector unfortnately. Railways suffer the same kind of treatment with out of control youngsters putting things on the line - sometimes causing derailments.
The other thing that the police will be wary of is, as has been said, people jumping off into the path of oncomig vehicles. My brother in law lost his wife this way one Christmas. It is something they will always attend very quickly - and the traffic monitoring cameras will pick you up quite quickly. people hanging around for a while will create a response, even if only to see what is going on. If you are doing this, try and be less obvious to the oncoming traffic - camera can see them, but once you have pushed the button you can drop down or step back a bit - distraction for drivers for one thing, looking up to see what you are or what is about to happen. I am ALWYS aware of people on overhead bridges and always very wary of them, ready to take avoiding action if need be. On a motorcycle you are very vulnerable - this time of year more so with evenings pulling in and the cold slowing reaction times.
