We all know that the Dartford Crossing will still be over capacity after a new crossing east of Gravesend is built – Highways England’s own forecasts say that there will still be between 136,700 and 138,900 vehicles a day at Dartford, which will increase up to 153,000 a day within 15 years. Since its capacity is only 135,000 a day, and the frequent tunnel closures for petrol tankers and high vehicles will still need to take place, we can be confident that the congestion at Dartford will continue and get worse.
But let’s consider Option C. Highways England forecasts that its preferred route will be used by 65,300 vehicles per day when it opens, increasing to 74,400 within 15 years. How will these vehicles get to and from the proposed new crossing?
Highways England forecasts that traffic using the A2 west of the A227 (Tollgate) will decrease by 19,400 vehicles a day. We can reasonably assume that this is traffic that would have used the Dartford Crossing, but which will in future use Option C.
Highways England also forecasts that traffic using the M2 between junction 2 (for the A228) and junction 1 (where the Option C link road joins) will increase by 27,300 vehicles a day. We can reasonably assume that this additional traffic will be made up from vehicles that would have previously used the M20, but which will now use the M2 to get to & from the new crossing.
Some of this will extra traffic will use the M2 and A2 all the way to & from Dover, but a significant amount will be using the A229 Blue Bell Hill and the A228 through Cuxton and Halling to get to & from the M20. This will have a serious impact on congestion on these roads and their junctions with the M2 and M20.
They also forecast that traffic using the A226 east of Gravesend will increase by 8,400 vehicles a day. This will presumably be made up with traffic going to & from the new junction on A226 between Chalk and Shorne. The extra traffic west of the new junction will be going to & from Gravesend, which will impact all the feeder routes, such as Thong Lane, Rochester Road, Old Road East, and Valley Drive.
The extra traffic east of the new junction will be going to & from Strood and the A289 Wainscott Bypass, since neither of these will have direct access to the link road.
So quickly doing the sums, we have 19,400 + 27,300 + 8,400 = 55,100 extra vehicles. But that is 10,200 short of the 65,300 vehicles predicted to use Option C.
If they’re not using the A2, and they’re not using the M2, and they’re not using the A226, which roads are these 10,200 vehicles going to use?
The only road left is the A227 through Meopham. This currently carries a fraction under 10,000 vehicles a day, so traffic through Meopham could potentially double. Much of this extra traffic will use rat runs through places like Sole Street, Cobham, and Shorne.
Note that this is when both the crossings at Dartford and the new crossing east of Gravesend are working normally. If there is an incident at Dartford, up to 139,000 extra vehicles would be diverted from the M25 to the new crossing east of Gravesend, on top of the 65,000 it is expected to carry.
In these circumstances, we can expect to see the A2, M2, A226, and all the connecting roads to be totally gridlocked.