Motorists will face a historic-high $6 charge when using the East Coast Parkway (ECP) during the morning peak.

The Land Transport Authority (LTA) in its latest quarterly review of Electronic Road Pricing (ERP) gantries said it was increasing the charges at the two gantries on the ECP heading to the city during the 8.30am to 9am slot from Aug 5.

The highest charges ever levied at ERP gantries before this latest announcement was $5 on the Central Expressway.

The LTA reviews the average speeds at its gantries regularly. It increases rates if average speeds fall below optimal levels. On expressways, the optimal average speed is between 45kmh and 65kmh.