By Caroline Wyatt BBC correspondent in Paris

The most noticeable thing about the recent "Paris sans Voiture" day (Paris without cars) was the number of cars on the roads.

Not in high heels yet, but happy to shake her fist - Caroline Wyatt

Cars everywhere, stuck in traffic jams, tailbacks all around the city as drivers refused to contemplate the idea of abandoning their battered Renaults and Peugeots.

Part of the centre of the city was strictly sealed off to all private vehicles; taxis, buses and emergency services were allowed, but nobody else.

Yet the very idea of going one day in 365 without a car provoked massive indignation among many Parisians.

My plumber, for example, who had been booked to restore the hot water at my flat after the boiler broke down was adamant.

"Without a car," he rang to tell me, it would be "absolument impossible" for him to work at all, so he was taking the day off instead.

Others took a similar view - even some cafe and restaurant owners along the Rue Montorgeuil, who had done their best to stay open during this spring's metro and bus strikes, shut down for the day.

PARISIAN TRAVEL FACTS 16 km/h is the average speed of a car in Paris 53% of Parisian households have no car 50% of air pollution comes from transport

"We've opened anyway, but a lot of others haven't as there'll be no customers if there are no cars," one caf� owner explained to me.

And yet Paris has some of the best public transport of any city I have ever lived in or visited.

The Paris metro is legendary for its efficiency - a train on the busiest lines every 3 or 4 minutes at least, the lines criss-crossing the whole of the capital and intersecting with the RER or regional urban railway network, which can zoom travellers from the city centre to Paris's airports in under 45 minutes.

Comical frustration

Likewise, Paris buses are among the most modern, comfortable forms of public transport, again frequent and reliable - and, like the metro, incredibly cheap.

A carnet of 10 tickets brings the cost of an individual ticket across town down to just 1 euro each or around 66p, less than half the cost of a similar journey on the London underground.

Of course all this comes at a price to the public purse.

Paris public transport is heavily subsidised - by high taxes.

And yet, at rush hour, the narrow streets of the city centre are crammed with cars, their drivers honking, shouting, waving fists at each other in almost comical frustration at the frequent traffic jams caused by an overload of traffic, parking cars and daytime van deliveries.

The rather smug expression on some of the van drivers' faces leads me to suspect they may be parking in the middle of narrow streets with malice aforethought.

Some fancy footwork can get you far in Paris

Certainly, the car drivers I vox popped in one of those delivery-van induced jams had very strong opinions about congestion on the streets of Paris, sadly none of them printable on a family internet site.

So what are the Paris authorities doing to improve life for Paris commuters and residents?

Paris' Socialist Mayor, Bertrand Delanoe, has already done a lot to help, says bus passenger Laura Pierre, an English teacher.

"He introduced bus lanes and more cycle lanes, and made sure the police enforce them with heavy fines for anyone caught in them illegally," she says.

"Before, no one took any notice so the buses were really slow. Now it's much better."

Style statement

Cyclists agree. They share the bus lanes, so fewer cars and more bus lanes are good news for them too.

Paris transport is famously efficient

After the summer heatwave, the mayor has had further ammunition to use in his campaign to discourage cars and give more space to public transport.

Now, he can also argue that public health is at risk thanks to excess pollution especially in the hot summer months as he tries to implement the following measures:

• Allow more "road space" for bicycles, buses, roller-bladers and pedestrians, for example by enlarging bus lanes

• Create more green spaces or "des quartiers verts" for pedestrians

• Entice more people to use public transport by creating 14 new bus lines across Paris (called "Mobilien")

• Create a tram line (opening in 2006) in the south and east of Paris

• Extend metro lines, improve RER stations, and increase the number of buses and metros

• Create a "river bus" service on the River Seine

• More spaces for bicycles to park

Despite the convenient Hotel de Ville metro station just near my flat, I have become one of the growing number of militant Paris cyclists, cycling to work and back every day up the Rue de Rivoli and then back home on the Rue de Faubourg-St Honore.

Timid at first, easily swayed (quite literally) by the motorbikes whizzing two inches (five centimetres) past my pedals, I now happily join in the waving of fists at pedestrians or lorry drivers hogging MY bus and cycle lane.

I don't yet cycle in high stiletto heels and tight skirts, as I've seen some smart Parisian women do on their way to work, but I am working on a slightly smarter outfit than my current tatty jeans and sneakers.