Concerns have been raised that fewer than 250 people a day are using a 1,000-space park-and-ride terminal to get into Leicester city centre.
Latest figures show an average of 248 people a day used the £5.25 million terminal at Birstall, to the north of the city, from the beginning of June to the end of August.
Officials from the city and county councils admitted numbers were lower than expected at the site, which opened in July last year.
They hope the service will ultimately cover its own costs but currently it is being heavily subsidised by the authorities.
The estimated subsidy for this year, for Birstall and its sister site in Enderby, is nearly £500,000.
The services were established to cut congestion, reduce carbon fumes with low-emission buses and, with the help of bus lanes, give people a quicker journeys.
Birstall county councillor Roger Wilson said: "I am sad to say the new site is very much underused.
"If you were to go during the week between 9am and 10am or 5pm and 6pm, it would always look very empty. Those are periods when we'd hope it would be busy.
"I support park-and-ride but it is having its problems and something needs to be done to get the numbers up."
In order to boost passenger numbers, a "Free Fridays" initiative is to be launched in October.
Passengers travelling from Birstall, Enderby and the third site, Meynell's Gorse, to the west of the city, will not be charged before 9am.
County Hall transport spokesman Lesley Pendleton said the use of the Birstall site was increasing slowly.
She said: "It's getting towards where we want it to be passenger-wise. but we have to do more to promote it with drivers and convince them it is a viable, affordable and convenient option.
"Passenger usage continues to increase and planned promotions will continue this increase across all the sites operating into Leicester."
Park and ride passengers using the buses yesterday said although the service was good, it would be hard to boost numbers significantly.
Helen Scruton, 39, of Loughborough, said she occasionally used the service to shop in the city centre.
She said: "It's good, well run and not too expensive, but nowhere near as good as being able to drive to within five minutes of where you want to go and park up.
"I think I'm fairly typical of most people and I just prefer having a car."
Alan Grant, 69, of Quorn, said: "It's a shame to see the big old car park mostly empty but I don't think you'll ever convince the vast majority of drivers to put the environment before their own convenience.
"I try and tell as many people as possible how good it is but, for most people, using it is a novelty rather than a norm."
