If the at-fault driver leaves the scene of the accident, you might be inclined to chase them. Avoid that inclination. Instead, document the make, model, and license plate for the vehicle and write down any details about the driver, passengers, or the vehicle that you can recall. Call the police immediately before taking any photos. Allow the police to collect evidence, but you should also photograph that evidence and get the names of any witnesses. Once you are equipped with all of that information, contact an Arlington, Texas lawyer about your next steps.