Minefield. If I were you, I would contact the local Council first, Highways Department, ask them. If that fails, phone the Police, Traffic Department, ask them for advice. Even after the installation is complete, you might still be causing a highway obstruction - if vehicles have to queue on the highway to drive into your company premises. You might need to plan for an articulated truck and trailer entering your site (for deliveries) and they can be 50 feet or 15.5 metres long, if they have to reverse into your site, they will certainly be blocking the highway. So then you have the nightmare of parked cars and car parking in general. Added to this blocking the footpath and the possibility of knocking a pedestrian down.

Just wait for the day when your fire / evacuation alarm goes off at peak vehicle arrival time ... our underground car park holds about 400 cars that all arrive in a 2 hour window. Because the alarms were going off our barriers were closed and no vehicles were permitted access, the queue of cars backing up wanting access just HAD to be seen!!