The study of whether electric vehicles are feasible for Singapore roads is set to move into its second phase.
The Land Transport Authority (LTA) said this could involve car-sharing and commercial fleets.
The LTA said that data collected from the initial two-and-a-half-year test-bed period, which ended in December last year, could be used to plan further trials.
LTA and the Energy Market Authority are leading the testing process.
But some stakeholders question if the government is being over-cautious in driving the scheme.
Electric vehicles have gained traction in the last decade or so.
They are made from recyclable materials, and have zero tail-pipe emissions, which helps the environment.
Experts also said electric cars could cost about a third to a quarter of a normal vehicle in running costs. To run an electric vehicle, it costs about S$5 in electricity per 100 kilometres. To run a comparable petrol vehicle, it costs about S$20 in petrol costs per 100 kilometres.
Electric cars are also quiet and offer a smoother ride.
Business owner Moy Saha, who rents an electric car from electric vehicle-sharing company Smove, said: "I also have another car, but it's easy for me to find parking with a smaller car. That's one of the big draws. If I'm going to places nearby, it's always easier with the electric car which just works out better than a much larger car."
"Range anxiety", or the fear that electric cars will not have enough charge to reach their destination, has been a concern for users in other countries.
But this is less of a challenge in a small country like Singapore.
The average daily driving distance for normal cars in Singapore is 55 kilometres.
Preliminary findings from the test-bed show that the average daily drive for electric vehicles is 41 kilometres.
The LTA said the first phase of the test-bed involved 53 organisations, including companies, government agencies and institutions of higher learning. 89 electric cars have been used on the roads.
On a full charge, cars under the test bed could reach a maximum daily distance of 115 kilometres.
But there are other concerns too. Some participants said there are too few charging stations.
Bosch Singapore, which rolls out the infrastructure in Singapore, said there are currently 75 charging stations with 118 charging spots around the country.
Another concern has been the hefty price tag for an electric car.
Test-bed participants can purchase cars under the government's Transport Technology Innovation Development Scheme.
This means they do not have to pay for costs such as the Certificate of Entitlement, road tax and registration feed.
But the trial is not open to the public, and buying an electric vehicle without tax rebates or incentives could cost about S$200,000 after COE.
Thomas Jakob, managing director of Bosch Asia Pacific, said: "The extra price is essentially the battery, so one of the incentives one could think about is to exclude the battery from the taxation scheme. Because that's driving a lot of the cost and through the taxation scheme, the battery becomes even more expensive over here, because it's a percentage of the cost or of the market value."
If the cost of privately owning an electric car remains prohibitive, there could be other solutions.
Smove is currently the only electric car-sharing player in the Singapore market.
But this could change in phase two of LTA's trial, if more of such companies are roped in.
Electric cars could also be used in micro-communities around Singapore, where distances are too far to walk, but too short to drive.
The National University of Singapore has been collaborating with Toyota Tsusho - the trading arm of the Toyota group - to test micro electric vehicles (EVs) around its campus.
The one-seater micro cars are classified as a four-wheel motorcycle. They use acid-based, rather than a lithium-based battery, so there is no allowance for luxuries like air-conditioning, which use a lot of power.
Researchers said current results show an average trip on such vehicles to be about two kilometres.
Assoc Prof Tan Kok Kiong from the Department of Electrical & Computer Engineering at the National University of Singapore said: "For me, before the micro EV, I used to go for meetings at other places within the university in my car, which is a seven-seater. So you can imagine a single person driving a seven-seater for a short trip, which is fairly inefficient.
"Eventually we could look at places like industrial parks, maybe even some places of interest, like Sentosa. Eventually, if all goes well, we might be able to contribute to the LTA masterplan which looks at providing a better mass transportation system."
Another option is electric taxis. Currently, there are some 28,000 regular taxis plying the roads.
Data show that in two shifts, each taxi could travel about 520 kilometres a day.
Nanyang Technological University researchers have been working with the Technical University Munich (Technische Universitat Munchen) to develop an electric taxi prototype for Singapore.
The prototype can be fully charged in 15 minutes, and travel distances of more than 200km per charge.
Experts said the power currently generated in Singapore could be enough even if all cars turn electric, even though the power supply usually works on a surplus strategy, so in the long term, an extra power station may need to be built.
Authorities said the test bed has shown favourable results for electric cars in Singapore in the future, but not immediately, or even in the next three years.
Some stakeholders are concerned Singapore could be moving too slow.
Joseph Ting, head of operations at Smove, said: "I'm sure the government has to be a lot more judicious in its use of public funds, so that's why it's taking a more cautious and conservative stand towards this test bed. But the risk there would be we could fall behind other countries in terms of the development of the electric vehicle industry in Singapore."
The government said it is looking for balance.
Josephine Teo, senior minister of state for transport, said: "If the price of electric vehicles is still at a level that vehicle owners find not to be very economical - not worth them making that choice, then no amount of effort that you put in the infrastructural areas is going to change that fact. These things have to move in tandem. Too early, it falls flat. Too late, then you don't catch the opportunity as well. "
For now, electric vehicles are generating some buzz on Singapore roads. But it remains to be seen if they will become a key mode of transport for the future