ERP 2.0 explained
ERP 2.0 and your OBU, explained
What actually changed when the gantries came down, what the three parts of the On-Board Unit do, what it can and can’t charge you for — and what it knows about your drive.
Last reviewed September 2026
What ERP 2.0 actually changed
The short version: the charging moved from the overhead gantry into your car. Under the old system, an arch over the road talked to the In-vehicle Unit (IU) on your windscreen. Under ERP 2.0, a satellite-based On-Board Unit (OBU) works out where you are and settles the charge itself, so the physical arch is no longer needed.
What did not change, at least at launch, is what you pay. ERP 2.0 reproduced the existing model — the same charging locations, now virtual, on the same schedule, with rates reviewed the same way. The technology underneath is new; the bill is meant to look familiar. For current rates and locations, always go to LTA’s ERP 2.0 page — those change on a quarterly review cycle and we don’t mirror them here.
The three parts of the OBU
In a car, the OBU is not one box. It is three, and knowing which is which makes the rest of this much easier to follow:
- The antenna. A small unit on the windscreen, on the right-hand side near the A-pillar. It handles the satellite positioning and the communication.
- The processing unit. Mounted in the right-hand side of the front passenger footwell. This is the brain, and it is also where your stored-value card goes — so it is the part that actually holds your balance.
- The touchscreen display. The part you see. It shows ERP charges, your card balance, and road and traffic alerts. This one is optional.
Motorcycles are the exception: the three components are combined into a single one-piece unit rather than split up.
Why the touchscreen is optional
The touchscreen was the most argued-over part of ERP 2.0, and LTA made it optional. You can have all three components and the full set of on-screen functions, or you can skip the touchscreen and get the key information through a compatible mobile application instead.
That second path is a real choice with real consequences, and it is worth understanding before you commit either way — we’ve written it up separately in no OBU touchscreen? what you can still see.
What the OBU charges you for
Road pricing is only one of the things the OBU settles. The unit distinguishes several business functions, and each one produces its own charge messages:
| Code | Name | What it covers |
|---|---|---|
| ERP | Electronic Road Pricing | The road-pricing charge itself, taken as you pass a charging point. |
| EEP | Enhanced Electronic Parking | Car-park charging that also carries the car-park operator’s own information, so the OBU can name the car park and show its rate. |
| EPS | Electronic Parking System | The established in-car-park payment scheme, charged through the same card. |
The unit reserves three further function codes (REP, OPC and CPT) that aren’t in use — they are placeholders for future schemes, so you may see them named in technical documentation without them ever charging you anything today.
For each of these, the OBU emits a short sequence you may recognise from the screen: an alert point as you approach, a pre-charging message, then either deduction successful or deduction failure. A failure almost always means the card, not the road — see how to check your OBU card balance.
What the OBU knows about your drive
Rather more than most drivers assume, and rather less than the worry suggests. Working from LTA’s own OBU developer library — the interface the Gantry app is built against — the unit reports:
- Your speed, derived from its satellite positioning.
- Your card balance and the card’s status, plus the payment mode in use.
- Each charge as it happens, with the amount and the charge type.
- A payment history of recent deductions.
- A trip summary — time and distance for the current trip, where a trip is simply ignition on to ignition off — and the total charged for that trip.
- Traffic and road messages: speed limits, school and Silver Zones, speed cameras, bus lanes, accidents, roadworks, lane closures, car-park availability and travel times. There is a fixed catalogue of these — we listed all of it in every alert your OBU can show you.
One thing worth stating plainly, because it comes up constantly: the interface LTA publishes for third-party apps is read-only. An app can see what the OBU reports. It cannot change how the OBU behaves, cannot enable or disable a stored-value card, and cannot alter what you are charged. That is a property of the interface itself, not a limitation any particular app will fix in a later version.
Is distance-based charging coming?
Not today. The system is capable of it, which is why the question keeps coming up, but it has not been implemented. The stated position is that distance-based charging is something to study once motorists have settled into the new system — not a switch being flipped now. If that changes it will be announced by LTA, and LTA is the place to check rather than us.
When you have to have one
All Singapore-registered vehicles are required to have an OBU installed by 1 January 2027, when ERP 2.0 is fully rolled out. Installation is being done free of charge during the roll-out programme, in phased waves by vehicle type, with the free installation period planned to close at the end of 2026. If you have been sent an appointment window, taking it is the cheap option.
Where Gantry fits. Gantry Display is a round AMOLED screen for your car that shows what the OBU reports — the charge as it happens, your card balance, your speed, and road alerts — positioned where you can actually see it, with the layout under your control. It’s an independent product, not an official LTA upgrade, and it is not affiliated with or endorsed by LTA. See what it does.