The precise whereabouts of your car will be tracked round the clock when the next generation Electronic Road Pricing (ERP) is switched on in about four years' time, reported The Straits Times.

Three consortia have submitted their bids in a tender that closed earlier this month, and are making their technical presentations to the Land Transport Authority (LTA).

They are NCS & MHI Engine System Asia; ST Electronics (Info-Comm Systems); and Watchdata Technologies & Beijing Watchdata System Co. ST Electronics has roped in computing giant IBM as a sub-contractor for its bid.

As early as August, the LTA will pick a winner, which will then have 42 months to deliver the system, according to tender documents. This means the system - the first of its kind in the world - should be up and running by 2019, although the LTA has said it will be operational "around 2020".

The authority has been tight-lipped about the new system, which has the potential to be implemented islandwide quite quickly. But it is likely to start off implementing it on roads that currently incur charges and defer on charging for distance clocked.

And although the system is touted to be 'gantry-less', there will be a lot more other street furniture such as beacons to boost satellite signals and cameras. "There will be a lot more fixed and mobile cameras around," said a senior executive with one of the bidding companies.

The most sophisticated piece of equipment, however, is likely to be the in-vehicle unit, which will have an in-built SIM card. Besides facilitating payment, it could have basic navigation functions and be able to tell the driver the ERP charges for the route he is taking.

"It will be like a smartphone in the car," the bidder said, adding that motorists will also be able to find out charges on 'a personalised portal'. Through this portal, a motorist will be able to plan his journey according to the cheapest or fastest route to his destination. "This on-board unit will be 'live' at all times, even when you have parked the car at home or in the office," he said, allowing the system to know a vehicle's location at all times.

Transport Minister Lui Tuck Yew has said that motorists' privacy will not be compromised as "we will anonymise and aggregate the data", referring to methods data collectors use to mask the identity of those tracked.

National University of Singapore transport researcher Lee Der Horng said the new system can still be intrusive as "every single movement of all motorised vehicles in Singapore can be tracked". But he said the system is a sharper anti-congestion tool. "It is capable of performing distance-based charging, charging based on degree of congestion, dynamic pricing, mixture of distance and congestion charging, and so on," he said. "Technically, driving speeds can also be monitored."

Carpark operators using electronic parking systems, however, may have to change their systems when the new ERP kicks in, as it is understood that the two systems are incompatible.