Another four electronic road pricing (ERP) gantries will have rates of up to $6 from next month, following two existing gantries on the East Coast Parkway as the most expensive ever.

In its latest quarterly revision of ERP rates, four gantries on the southbound Central Expressway (CTE) after Braddell Road and on slip roads leading into that expressway will charge $6 between 8.30am and 9am.

The previous rate on those gantries was $5. The Land Transport Authority said the revised rates will apply from next Monday.

Rates for the other gantries will remain unchanged, and the next ERP review will take place next month for the December school holiday period.