One specific aerodynamic test Catesby Tunnel is perfectly set up to accommodate is a coastdown. The length of the tunnel means there is ample time to accelerate a vehicle up to typical speeds of 130-180kph before putting it into neutral and allowing speed to decay. The combination of constant environmental conditions and an incredibly smooth asphalt surface makes repeatability in the tunnel outstanding. This means tiny changes, such as placing a small camera mount to a vehicle can be easily spotted in the data.
Catesby Tunnel obtained VCA certification of the facility for WLTP coast down in early 2023.