Cars on the roads...

I have just edited this suggestion after receiving useful feedback and having conversation about some of the details.

In order to tackle pollution and congestion as we come out of lockdown we divide all traffic in two by only allowing cars with an odd or an even number plate to drive on the roads on certain days of the week, Monday-Saturday, three days on three days off. This will be applied at specific times of day and rather than numeric could even be alphabetic (A-M cars and N-Z cars).

Either way its an easy visual identification that restricts the amount of traffic for six days of the week. 

I suggest we first trial this on a section of road somewhere that gets congested, perhaps use two or three lanes of the M4 corridor around Newport and further extend it if it is a success.  Overhead matrix boards will say only cars adhering to this system can drive in lanes 3 and 4 (the hard shoulder is not disturbed and is still accessible for all traffic). Once decided on, the days cant be changed as people need time to make arrangements. Drivers don’t need to sign up to anything, as long as they drive in the correct lanes on the correct days they won’t get fined. ANPR cameras check cars are adhering and fines go to pay for it all. There will likely be some drivers that will just try to find an alternative route around the motorway but if a driver is sitting in congested traffic in one lane, seeing traffic moving at a good pace in the next lane, I think it will encourage more people to get involved rather than try and find alternative routes.

It will only work if this runs alongside increased help for drivers to find alternatives on the days they can’t drive. Drivers don't need to sign up to anything but if they do they are sent detailed information on public transport either by post or regular SMS updates and more importantly a tried and tested car share app is provided that encourages drivers to give people lifts and find lifts for the days they can’t drive. These kind of car sharing apps are available and perhaps worth looking at.
The app/website I have in mind is a cross between Airbnb and Uber. When a user inputs their cars registration the app gives out a calendar of exact days and times that car can and cant use specified lanes in the trial. It also makes it simple to car share for chosen time and direction of travel in the area of the trial. It would be run by government and have a bit more credibility for the target user group than any of the currently available car share projects.

A big problem is that most people have access to more than one car so have the option of using another car when they cant use their own. I suggest that the app gives incentive 'points' or 'credits' to a driver and the driver has to first register just one car that they wish to use on the app. A disabled driver can only register one car for tax exemption but may own more than one car, they just don't get the same tax relief. When a user of the app doesn’t use their car and accepts a lift from another app/road users on the days they can't drive, they are given credits. That way, rather than just using their other half's car when they cant drive their own car they are encouraged to get more involved. The aim here is to boost lift sharing and cut down congestion in the trial area. Users of the app can leave feedback, good points, bad points, reviews etc. and they will get credits the more people that they give lifts to and the more lifts they take.  There has to be a worthwhile benefit when an amount of credit is reached. Financial benefit is always best, free/half price tickets on public transport, road tax reduction or rebate maybe? There could even be other perks like tickets to rugby, music concerts, family days out. There can also be a phone-line that drivers can call to get involved in the system so it doesn't exclude all those drivers who don't use computers or smart phones. The system can even call/message drivers on a certain route if lifts are needed, even at short notice. EG a driver could receive a text saying "lift required tomorrow @ 8 A.M. from Cardiff to Chepstow, 70 credits" the system can send this message out to all the drivers it knows that drive in that area on that day. As much as possible is available by phone and SMS too, not everyone can download apps.

Its already been tried in other countries and we can learn from their problems, eg government and staff don't get a pass they lead by example and car share, or use the train etc...

There was also a lift share project that ran for a year on Bristol A4174 ring road. I remember you had a lane during rush hour where only cars with multiple occupants could use and there was a fine if rule was broken, cameras enforced it. I dont know how successful it was, but I know it didnt have any alternative arrangements for drivers running alongside it.
This is the trial if anyone from Plaid wants to ask them the contact is on here: https://consultations.southglos.gov.uk/consult.ti/A4174HOVlanesamendments/consultationHom

I don’t think Wales are developing any of these expensive ‘smart motorways’ which have been called dangerous by many individuals and groups in England, including the person who first suggested it I just read. I hope this sort of system will better manage the increased pressure on our roads.

Obviously there should be a free pass for nurses/doctors/teachers etc.