A new park and ride for Bristol will be built on the M32 motorway as part of a bendy bus route through the city.

It will provide an alternative to thousands of commuters who drive in and out of the city every day.

A 1,500-space park and ride site would be part of a £191m package to build a rapid transit system from Stoke Gifford on the northern fringe of the city into the city centre and threading through south Bristol to Hengrove.

The aim is to win approval in the autumn, 2011 and see the scheme up and running by the end of 2013.

But the allotment holders today promised to fight any moves to take away their plots.

It will be Bristol's fourth park and ride.

The others are in Brislington, Long Ashton and Shirehampton.

The first, at Brislington, was opened by the former Avon County Council in the early Nineties.

The preferred site for the new M32 park and ride is next to the motorway close to junction one, on land between the motorway and Frenchay Park Road, currently used as allotments and known locally as Stapleton Smallholdings.

The other four sites are:

● Hambrook: this site lies on the northern side of the A4174 Avon Ring Road and near the M32.

Issues: it would be costly to buy the site and build a long access road. The site is said to be liable to flooding. Thirdly, the distance from the motorway would mean fewer people would be likely to use it and it would clog up the Avon Ring Road even more.

● Hillside Gardens West: this site lies next to the M32, south of Filton Road.

Issues: this site is regarded as too close to Junction 1 of the M32 where it meets the Avon Ring Road. Highways experts say that even if an access road could be built from the ring road, then the impact on traffic flows would be too difficult to manage.

● Hillside Gardens East: site lies between the M32 and Frenchay Park Road. It is not favoured for the same reasons as Hillside Gardens West.

● Broomhill: this site is the nearest to Bristol, lying between the M32 and Frenchay Park Road and south of Stoke Lane.

Issues: it would be using part of the historic landscape in Stoke Park and there is no room left to provide a safe motorway junction. There is also not enough room to provide enough landscaping and environmental improvements to safeguard the quality of life for residents who live nearby.

Bristol transport leader, Lib Dem cabinet councillor Dr Jon Rogers, said Bristol suffered from congestion and poor public transport links which meant that something needed to be done.

He said: "Successive administrations have identified the need for a park and ride site for the M32 corridor. Unfortunately, this means not shying from difficult decisions."

He stressed that no decisions had yet been taken and it was a priority for him that information was relayed to people so they could put forward their views and comments on the issue.

He said further talks would be held with the Highways Agency and the West of England Partnership – a body which represents the four councils in the former Avon area.

Nick Sturge, chairman of the Institute of Directors in Bristol, said: "I think some form of rapid transit system to connect different parts of the city is a good thing.

"But we have to work together in order to achieve this and that will inevitably mean making compromises.

"Unfortunately, in order to achieve long-term gain, there is bound to be some short-term pain.

"Something has to be done in order to sort out the traffic problems in the city. Providing fast, reliable and safe public transport is by far the best way to do this.

"A rapid transit scheme on its own is not the answer – we need a strategic transport network which is properly managed."

But nearly 90 allotment holders in Stapleton are in danger of losing their plots to make way for the M32 park and ride site.

The prime agricultural land in the greenbelt is one of five sites which have been shortlisted by highways experts for the scheme to ease congestion on the motorway into Bristol.

Allotment rep Barry O'Rourke said: "I'm amazed they are even thinking about using this site. During the last couple of years, the council has spent a lot of money on new water butts and new gates and now the site is very popular.

"There are 87 plots and I think only four are vacant.

"A lot of us have worked the land for years and it's not easy to give up.

Mr O'Rourke, 46, a production engineer of Kings Drive, said they might be offered somewhere else but it would not be the same.

He said: "We've put our backs into that land and it means something very special to us.

"We will be launching a campaign to prevent our plots being taken away from us.

"We understand the land has a covenant which means that it cannot be used for anything else but allotments. We plan to take legal advice on this."

Dr Rogers added: "At this stage, it appears that Stapleton Smallholdings is a prime contender but the irony and challenge is not lost on me.

"We would need to protect local food production in and around the city and any loss of allotment or smallholdings must be replaced."

Councillor Lesley Alexander (Conservative, Frome Vale) has already presented a petition to the council with 2,500 names because of fears over the loss of the allotment site.

It was highlighted as a possible park and ride site a couple of years ago but no firm plans were submitted.

Mrs Alexander said: "We're talking about grade one agricultural land providing the best soil in Bristol and in the greenbelt.

"If we had a park and ride site here, then it would make pollution 10 times worse.

"Then there is the issue about the covenant – I believe the land was given by the Duke of Beaufort on the understanding that it would never be built on.

"There is also the issue about access – ambulances have enough difficulty getting through Frenchay Park Road as it is.

"It doesn't make any sense at all to take away these allotments for a park and ride site."