The National Infrastructure Commission (NIC), an agency responsible for providing advice to the U.K. government on the matter of domestic infrastructure, said that major English cities outside of London should introduce a type of congestion charge to reduce traffic and boost local economies.

According to The Guardian, the Commission asked the government to invest over $26.7 billion in public transportation systems in Manchester, Leeds, Bristol and Birmingham. The Commission warned that “congested roads and inadequate public transport… constrains their economic growth.”

The NIC said that investing in intra-city links would increase transportation capacity. Moreover, the organization claimed that congestion charging or workplace parking schemes would be necessary to limit traffic in city centers.

“You don’t unlock economic growth by clogging up cities,” said Sir John Armitt, chair of the NIC.

He also said that creating the congestion charges should be left up to local city authorities. “What is done locally has to be a local decision,” he said.

Armitt added that the country should prioritize the maintenance of existing infrastructure, arguing that both Network Rail and National Highways will need more financing to counteract the effects of climate change.

These suggestions came just before the NIC released its National Infrastructure Assessment on October 18, which claimed that the Prime Minister’s choice to halt construction of the northern leg of the HS2 high-speed railway left “a major gap” in the country’s rail strategy.

“Where until recently we had a long-term integrated strategy, we now have a collection of projects,” said Armitt. “I would hope that the future possibility of recovering that scheme [HS2 to Manchester] remains on the table.”