Mayor's summer experiment of a car-free motorway faces test in court

An ecological and political battle over the banning of cars from an urban motorway beside the river Seine will spill over into the courts on Wednesday.

A Parisian lawyer will accuse the new, Socialist mayor of Paris, Bertrand Delanoe, and the city's police chief, Jean-Paul Proust, of illegally blocking the public highway.

As an experiment which may become permanent, Mr Delanoe has banned cars from the Voie Georges Pompidou, the 30-year-old west-to-east expressway on the lower quais of the Seine in central Paris.

From mid-July until Wednesday of next week, the two-lane, fast route through the heart of the French capital has been reserved for pedestrians, cyclists and roller-skaters, to the joy of tourists and some locals.

But car-oriented Parisians, taxi drivers and centre-right political parties have been incensed. They say the closure of the riverside motorway has caused enormous traffic jams in other parts of the city. It did at first, but the traditional August departure of many Parisians for traffic jams further south eased the problem.

A Parisian lawyer, Maître Michel Fleury, will today argue before the tribunal de grande instance that Mayor Delanoe and Mr Proust, who form the supreme police authority in Paris, had no right to close the Voie Georges Pompidou to cars, even for a month.

"The mayor wanted to send a signal to motorists and discourage them from coming into the city by car but it is not the job of a police authority to send political messages," he said.

Mr Fleury will also complain before the court that the closure of the Voie Georges Pompidou could "slow down ambulances and emergency vehicles and cost lives".

The court has agreed to fast-track its hearing of the lawyer's complaint, but will not give its decision until next week. Even if it decides against the Mayor, therefore, the summer experiment with a car-free Seine will not be interrupted.

But a defeat in court would undermine Mr Delanoe's long-term plans, promised in his campaign to become Mayor last March, to ban cars permanently from the Voie Georges Pompidou and a similar east-to-west expressway along the Left Bank close to the Eiffel Tower.

Before going ahead with permanent closures, Mr Delanoe's team has promised to improve the traffic pattern elsewhere in the city and reduce the number of people commuting in cars daily from the suburbs.

The experimental closure proved an embarrassment at first. It rained and few pedestrians or cyclists dared to stray on to the motorway where cars had once ruled.

But in the past two weeks, as word spread, the Voie Georges Pompidou has been overrun with walkers, cyclists and, especially, roller-skaters.

At the weekend, in a symbolic celebration of an "ecological" victory over the car, prominent members of the Verts, the French green party, informally rebaptised the motorway as the "Voie de la Vélorution" – or Avenue of the Cycling Revolution.

Mr Delanoe, who is on holiday in Tunisia, said the action was "lacking in the respect due to the late president [Georges Pompidou]".