n.b. I started writing this post in a different era, on Monday afternoon, when its contents might have mattered.
This is Beech Street in the City of London.
Less a road, more a tunnel, Beech Street slots beneath the concrete podium of the Barbican estate. But its confined nature also increases air pollution, which is why today it becomes the City's first Zero Emission Street. They could have done this by banning all vehicles, but instead they're only allowing zero emission vehicles (and of course cyclists and pedestrians).
'Zero emission vehicles' don't necessarily have to have zero emissions. The actual standard is the same as for the Cleaner Vehicle Discount for the Congestion Charge, i.e.
• Maximum 75 g CO2/km
• Minimum 20 mile zero emission range
• Euro 6 equivalent NOx emission standard
But most vehicles have been banned from the street overnight.
Route 153 won't need diverting because it uses electric buses. So that's been carefully thought through.
However, several vehicles with non-zero emissions will be permitted to drive down Beech Street, because they need to reach the car parks in the middle. Two of these are for residents of Cromwell Tower, Shakespeare Tower and Defoe House, and one is the main car park for visitors to the Barbican Centre. Also, those who work at the vault-like Barbican Trade Centre are allowed to drive their cars and vans along Beech Street because it's the only way in.
The City is enforcing the ban using cameras at each end of the street. Non-compliant vehicles will be subject to a Penalty Charge Notice if they drive in and out within a certain time period. However vehicles accessing off-street premises, including car parks, won't pass the second camera within the specified interval so won't be charged.
Initially it's an 18 month trial, during which time measurements will be reviewed to see if air quality has been improved. The hope is that NO2 levels fall from 50 µg/m³ to nearer 30 µg/m³, which should benefit all those in the vicinity including two nearby schools. However NO2 levels on London Wall, which runs parallel, are predicted to nudge above recommended limits as a result, so it's not all rosy.
I would show you a photo of the special signs erected at each end of the street, but these were covered up when I visited and I can't go back today because that would be "unnecessary travel". Indeed the coronavirus crisis could have solved Beech Street's pollution problem by deterring vehicles and the pedestrians breathing their emissions. The environment may be the one big winner out of all of this.