If you find it harder to catch a cab these days, it could be because as many as 2,000 of them are lying idle in yards instead of plying the roads.

Higher rental rates, stricter service standards, competition from newcomers such as Uber and GrabCar, and higher incidence of traffic summonses have prompted many cabbies to give up driving taxis.

Trans-Cab, the second largest cab operator here, is one of the biggest victims of this fallout. When The Straits Times visited its premises in Defu and Sungei Kadut last week, there were as many as 800 red taxis parked bumper to bumper, many covered with a visible layer of dust.

The number could work out to 15 per cent of its fleet - the highest unhired rate since Premier Taxis could not hire out 10 per cent of its fleet in early 2009.

"Uber and GrabCar," managing director Teo Kiang Ang said immediately when asked about the situation. "These companies don't have to follow the LTA (Land Transport Authority) rules on taxi availability. They use nine- to 10-year-old cars; we cannot. They pay very low insurance premiums.

"They're having a free lunch."

Even if the other operators experienced a fraction of Trans-Cab's unhired rate, the number of cabs lying idle is likely to exceed 2,000.

Premier Taxis chairman Timothy Chua said there has been a dip in his fleet's hired-out rate, "but the alarm bells have not rung yet".

"There aren't enough drivers," he said. "It's hard to find good drivers."

Dr Lee Der-Horng, a transport researcher with the National University of Singapore, said the whole industry is affected by drivers switching to the likes of Uber and GrabCar. But the smaller cab operators are bearing the brunt of this, possibly because their drivers are not getting enough call bookings from their own dispatch systems.

"Having experienced the benefits of those taxi apps as compared to their own dispatch system, they switch," said Dr Lee.

"In future, nobody will want to be a taxi driver," he said. "The Government must do something."

ComfortDelGro, which accounts for 60 per cent of Singapore's total fleet of 28,600 cabs, declined to comment on the number of its taxis which are not hired out, saying it was "competitive information".

However, a stock analyst, who is covering the transport giant, said it was considering rolling out new incentives to attract drivers in the light of new competition. SMRT is doing likewise, confirmed its spokesman Patrick Nathan.

However, these may not be enough for some cabbies, who said driving a cab has become harder with new service standards stipulating that a taxi must clock at least 250km a day. "With Uber or Grab, you don't have to do this," said one. "You just wait for business to come to your phone."

With the roll-out of more bus lanes and illegal parking enforcement cameras, cabbies are also facing more fines now.

Trans-Cab cabby Francis Goh, 61, said: "Since taxis are a form of public transport, why not let us use the bus lanes as long as we don't stop?"

However, the single biggest factor behind the idle taxis is the higher rental rate. Daily rentals now range from around $130 for a regular cab to about $180 for a new Mercedes-Benz taxi - 50 per cent to 60 per cent higher than a decade ago.

The rental for an Uber car is as low as $60 a day.

An industry source said 30 per cent to 40 per cent of drivers who signed up with Uber and GrabCar fleets are former cabbies. There are an estimated 3,000 of such cars providing on-call taxi services.

Cabbies who have switched said attractions include having access to a car that does not have a taxi sign on its roof, and being able to fetch clients to Malaysia and back.

Mr Thomas Tan, 50, was among half a dozen cabbies who had given up their Comfort Mercedes cabs for Toyota Alphard MPVs.

"This is the new direction, and we're embracing it," he said.

His colleague Leslie Chang, 46, said: "This is like having our own car with a private number plate."

On average, Mr Chang said he does five to eight trips a day. "In a taxi, we had to do 20," he noted.

They pay less than $140 a day on rental, versus $178 for the Merc.

The LTA said 3.8 per cent of taxis - or more than 1,000 - were unhired as at June. Observers reckon the figure has climbed since.