I assume your solicitor can uickly get access to the Land Registry site, I can, and I am not a solicitor and get a copy of the plan for the land you own and the access agreement that must exist between you and the other house owners who need this road for access.
Presumably the road is therefore a private road, unadopted by the council and maintained by you and the other house owners who use it. It sounds as if this is a private road, and not part of the public highway. Could you put up a sign that says 'Private Road, Access only?
I would be chasing my solicitor up every day in your situation, to make sure they understand the urgency of the situation and are acting fast.