Eventually I found a minicab and was able to pay my way out. Most young Vitrollois can't. Ask any one of the dozens of young men standing around in the sunshine. They feel neglected - and stuck.
One-third of the way between Marseilles and Avignon, with neither the bustle and opportunity of the former nor the dignity and elegance of the latter, Vitrolles is an almost completely new city - a cross between Harlow in Essex and a lesser Los Angeles. Built as a series of landscaped estates, with a complex of central squares and a shopping precinct in the middle, it was supposed to be people-friendly.
In practice, the A7 motorway cuts Vitrolles in two. It is too extended to walk around, and there is nowhere particular to walk to. It was built to accommodate workers serving the vast new industrial complexes that spilt out of northern Marseilles. But then the local (Socialist) authorities upped employers' taxes, and the factories and warehouses started closing down.
There are some smart Provencal villas near the remnants of the old village. Most of the inhabitants, though, live in council flats. They are predominantly young: many are the children of immigrant parents, and they have nothing much to do.
Last week, 43 per cent of Vitrolles' electors who bothered to turn out voted for the extreme right National Front candidate, Bruno Magret, to be their next mayor. The result shocked France, and yesterday all the main national television stations were in Vitrolles, preparing for the eventuality it would become the first 30,000-plus city to elect a National Front mayor.
There were no shortage of people to explain the situation. "Ask any of us, the French," went a typical comment. "There's too many of them, the North Africans, the Arabs, and they have a different idea of the law." All the talk among the elderly French people in the cafe at lunch-time was of crime and drugs and how nothing was being done about it.
Mr Magret, it has to be said, is not your average National Front thug. His academic qualifications rival those of France's mainstream politicians. He is articulate and presentable, and would make a plausible candidate for any party. Given the plight of Vitrolles, you can understand its voters thinking he might do a better job of representing their cause than others in the field, including the outgoing Socialist, Jean-Jacques Anglade.
Equally understandably, the "foreigners" - many of whom are French citizens by birth - are worried. In one of the squares yesterday, with the town hall behind them and a steady trickle of people going in to vote, clusters of young men, mostly black and brown, stood watching the market pack up. Police vans cruised the estates; there were more police on motorbikes. And as I left in the late afternoon, a dozen busloads of riot police were coming off the motorway. Just in case.