‘Through the Looking Glass’ economics used to justify a new P&R at Hauxton

The Greater Cambridge Partnership (GCP) has published the (722 page) Outline Business Case for a new 2,260-space Park & Ride on the Hauxton side of the M11–A10 interchange. The ‘preferred’ option includes two new junctions on the A10, a new road over the existing farm bridge into Trumpington P&R, a new cycle/footbridge over the motorway, and more bus lanes along Trumpington Rd.

The monetised benefits are minus £23 million. That’s right, the benefits (before subtracting costs) are negative. That makes for a benefit-to-cost ratio (BCR) below zero, i.e. we’d be spending money to lose more! In HM Treasury’s understated terminology, this counts as “very poor value for money.”

No matter, the report asserts, “when the benefits are less than the costs the actual BCR becomes irrelevant…” This is ‘Through the Looking Glass’ economics. Cost-benefit analysis is certainly flawed, but it’s the best tool we have for comparing projects to help decide which to prioritise. In this case it provides a very strong signal that the £55 million or £24,500 per parking space (in 2019 prices) would be better spent in other ways.

Still, let’s indulge GCP: perhaps a new P&R at Hauxton really is the only game in town, and significant benefits are missed by standard cost-benefit analysis. What will it do for traffic in the area? Well, on every single metric, the ‘preferred’ option scores worse than all scenarios considered, including not building the P&R. Drivers will experience an average delay of nine minutes, compared with two now; average speeds will fall from 30mph to 13mph, and below 7mph between 5pm and 6pm. Queues on the M11 could extend for two miles.

To pursue a scheme that will waste so much taxpayers’ money and make life in villages along the A10 intolerable can only be explained by institutional inertia and a desperate lack of imagination.

Park & Ride was the right solution in the 90s. Now we need comprehensive, integrated public transport. That means building travel hubs and cycleways throughout the county; redesigning bus networks; and funding more frequent, cheaper bus services from 6am to 11pm.

We would urge all readers to give the GCP and councillors their opinion on this scheme. We have created a reply form to make it easy here. You can use it to just send our provided reply, or write your own.

This article was first published in the Cambridge Independent on 19 June 2019. A correction was made on 23 June: the proposed number of parking spaces at Hauxton is 2,260, not 946. This reduces the cost per space from £58,000 to £24,500.