In its Annual Monitoring Report, published today, the National Infrastructure Commission (NIC) also renewed its call for the preparation of a "spatial vision" for the Oxford-Cambridge growth arc and the announcement of new settlement locations.
The report says that, in 2019, although the rate of housebuilding has increased in the Cambridge-Milton Keynes-Oxford arc, "there is still a long way to go and no clear plans have been brought forward to increase the delivery of new homes to reach the levels needed".
It says there had been "limited progress on the major decisions required both to improve transport connectivity across the arc, and to effectively integrate road and rail schemes with major new housing developments".
It says that, in 2020, the government "should clarify its position and take key route decisions on the Oxford-Cambridge Expressway". In December, transport secretary Grant Shapps announced that plans for the expressway linking Oxford and Cambridge would be put under review if the Conservatives were re-elected.
The NIC also says the government should "maintain momentum on East West Rail following the recent announcement of the preferred route between Bedford and Cambridge".
It adds that the government "should demonstrate clear ministerial ownership" for the Cambridge-Milton Keynes-Oxford arc and "publish timetables for the development of a spatial vision, as well as announcing the locations for new settlements in connection to major transport schemes".
The NIC made a similar call for progress on the spatial vision and the designation of new settlements in March last year.
Elsewhere, the document says that ministers should "commit to building an affordable Crossrail 2 at the forthcoming Spending Review".
It says that, despite the ongoing need for increased rail capacity in London, "continued delays mean that Crossrail 2 is now unlikely to open until the late 2030s at the earliest".
The NIC said: "This misses all the Commission’s recommended deadlines. And it will delay the benefits Crossrail 2 will bring to London, the surrounding area and the UK’s economy."
The government made a commitment in 2018 to appoint a "ministerial champion for the arc" but has yet to make an announcement. However, Paul Maynard is the minister responsible for East West Rail.