A judge, still wearing his robes, wandered through traffic, ordering drivers to put on their seat belts.
They had argued that they were unwilling to order drivers to make shipments because of fear for their safety.
The city itself even got into the spirit, ordering drivers to avoid honking, which might disturb students, and, in some places, closing down Internet cafes in the days before, to encourage studying.
But though there were signs that small numbers of oil trucks were carrying fuel from depots late tonight and though there has been no violence, many companies seemed reluctant to order drivers to cross the protesters' informal picket lines.
According to www.auto.ru, an automotive enthusiasts' Internet chat room that chronicled the tie-up, a band of furious drivers ordered a truck driver to turn off his idling engine.
The students threw themselves flat on the floor but ordered the drivers to keep going.
In order to conserve fuel and ensure the cars finished the Ferrari team ordered both drivers to slow down.
The officer, the statement said, "ordered the driver to stop, and opened the driver's side door when he failed to comply".
The second threat, the officers said, comes from criminals, some of whom masquerade as police officers and order drivers to pull over.
The police sometimes draw their guns and order drivers in vehicles similar to the two that witnesses have described to come out with their hands up and prove they are not the sniper, an official said today.
