Witnesses are your birds-eye-view so to speak and will help to add clarity to the situation.
The thing you have to keep in mind is the more information you can gather at the scene of the accident the better. If possible, take pictures of the damage done, injuries, street signs, etc. No information you gather will hurt you, but not having enough certainly can.
The mess doesn’t just end at the site of the accident, however. Something you’ll soon discover when placed in such a situation is that dealing with the insurance company or the actual person involved isn’t always as easy as you’d hope. People will sometimes flake out on you, say they are going to pay then never answer the phone, or when the time comes, outright refuse. The same goes for insurance companies. Some will fight you on every point. There are plenty of cases where insurance companies don’t want to pay out nearly what they should, or anything at all.
After the fact there are many places you can go to seek advice. It’s always suggested that you contact a lawyer in any sort of accident with significant property or bodily damages—ask around your local scene for lawyers in your area who have handled bicycling cases in the past. There are a number of resources on the web to help as well, for me it was www.mybikelaw.com. Luckily for me I live in South Carolina and just around the corner from one of the lawyers on the site. Often lawyers are willing to sit down and lend advice in which direction to go pro bono, or for a small fee. While maligned in other circumstances as the victim of an accident your lawyer is on your side, and their expertise could be worth their weight in gold.
In my particular case, even with the driver’s information I still thought it best to seek legal guidance, and ultimately representation. Most of the time in personal injury cases the lawyer won’t charge a fee if you don’t receive a settlement, and most often their fees won’t come out of your property damages. The way it worked out for me, I got reimbursed very quickly for my totaled bike and torn up messenger bag. My particular attorney took a third of my medical settlement, the remaining two thirds of which was more than enough to cover my expenses.
When an accident occurs it’s important that our rights are protected and upheld to their full extent. It’s important to gather as much information about the accident as possible and to seek the appropriate legal advice. While there are many situations where cyclists are hit at the fault of someone else, it is also our responsibility as cyclists to abide by the laws that govern us on the roadways—to not only look out for ourselves but those around us.