The really simple, low-tech, cost-effective, existing technology can be put in place in across the entire motorway network in weeks and begin preventing wrong-way driving at selected sites in days.
Decades ago in car parks, metal plates on pivots were inserted into the driving surface. Drive across them in the right direction and they'd simply collapse and flatten in front of your tyres. Once you'd driven over them, gravity reactivated them and they were primed for action again.
Drive over them the wrong way and they puncture your tyres, incapacitating your vehicle.
There is no need to dig up roads. The metal matrices are manufactured off-site, delivered to the off-ramps, reassembled, and anchored by means of holes drilled into the road surface. The off-ramp is out of service for from 12-24 hours to allow the quick drying cement to dry and to allow for testing. Simplez.
While they're at it, whichever of the multifarious QUANGOs we suffer from in this poor country might look at how a car managed to drive through the flimsy railings on an M50 flyover and end up on the motorway. Surely Aramco is what's required in these situations or are we still building motorway safety down to a price, including back-handers, rather than up to a standard?
IIban available on request.