Is it legal to file a lawsuit for a car accident in a different city from where it occurred?

There are many different bases for venue.  I'm not familiar with Texas law, but un New York, one proper place for venue would be the county in which the accident occurred, another would be the county in which the plaintiff resides, which is probably the basis for venue here.  Also, if this lawsuit was filed shortly after the accident occurred, you generally would have a limited time to object to venue or would have waived the objection (if the lawsuit was only filed recently, 10 years after the accident ocucrred, it is likely that the statute of limitations has run(.