should I sue?

First thing I'd do, if you haven't already, is get the formal written snow removal policy from the town. They better have one in place for due diligence and town insurance coverage. Go through it line by line and you might get lucky to find that snow that is packed up against concrete barriers is supposed to be removed (within 24 hrs.) to stop the ramp effect. The policy should also include the primary and secondary snow removal areas such as school zones and emergency routes. If any of this stuff is missing then ya got something to beat them around the ears with at the next town council meeting and maybe embarrass the hell out of the people that are supposed to be running the show. You might be able to argue that the snow removal boss let a dangerous situation exist by not removing the snow that was packed against the concrete barriers. To our friends down south, yes most towns and cities have snow removal policies and budgets in place and have had for many years, where we live and the insurance companies demand it and a portion of our property taxes goes to pay for it.