Contractors for the Highways Agency were guilty of a "very serious lapse" in not getting roads gritted in time to avoid gridlock on major routes in January, a report by MPs said yesterday.

Salting began "too late to prevent chaos" in the northern home counties, according to the transport committee's report, The Work of the Highways Agency.

It said it was "utterly astounding" that a breakdown in radio communications involving a gritter lorry fleet in the area worst hit by the weather lasted for four days. It added that it was also "intolerable" that the agency had no immediate financial sanction available when a contractor failed to keep roads open and free of ice.

Many drivers were stuck in their vehicles all night on January 30-31, with areas north of London and the M11 in particular experiencing appalling driving conditions.

The report said one contractor, Carillion-URS, had not gritted roads because of an above-zero temperature forecast.