The RM4.5 billion Second Penang Bridge is expected to open to traffic in February next year after completion of the North-South Expressway (NSE) toll system and bridge physical safety testing.

Works Minister Datuk Fadillah Yusof said the NSE toll system had to be upgraded as users were required to pay a toll charge when they leave the expressway to enter the bridge.

"We are still making improvements and will open the bridge when the system functions well and is certified safe," he told reporters after visiting the bridge, Thursday.

He said the 28-booth toll plaza in Batu Kawan would be the biggest of its kind in the country, but the government had yet to decide on the toll rate.

The Second Penang Bridge, which covers 24km with 16.9km over water and links Batu Maung on the island to Batu Kawan on the mainland, abided by environmental sustainability in design and construction.

Being Southeast Asia's longest bridge, the Second Penang Bridge is expected to ease traffic congestion on the Penang Bridge by 25 per cent.

Responding to a question, Fadillah said toll charges along 29 expressways in the country were being revised between three and five years, depending on the concession agreement.