Strikes will affect the railways and roads in the coming days, prompting highways chiefs to urge drivers to plan ahead.
National Highways, the agency that is responsible for motorways and trunk roads, said that the roads were likely to be busy – and the weather looked likely to be wet.
The agency said: “National Highways is urging motorists to plan ahead for journeys in the new year as traffic levels return to normal after the Christmas break.
“Members of the PCS union at National Highways are planning a national strike on Tuesday 3 January and Wednesday 4 January – the first working days after the holiday season in England.
“National Highways has put in place well-rehearsed resilience plans to ensure that the 4,500-mile strategic road network remains open and safe at all times.
“Resources can be shared between regional control centres if some areas are low on staff numbers this week, with colleagues elsewhere assisting with call handling and the setting of signs and signals.
“Separately, for on-road traffic officers, National Highways is able to divert colleagues from patrols on all-purpose trunk roads to busier motorways where needed.
“National Highways is confident that the forthcoming industrial action will have minimal overall impact.
“Nevertheless, roads are likely to be busy on both days and drivers are being asked to plan ahead, particularly with national rail strikes being staged at the same time.
“It is advising people to check the National Highways traffic website for road conditions and any congestion before embarking on a journey.
“Motorists should also ensure that vehicles are safe and roadworthy, with the correct amount of fuel for their journey.
“Vehicle information can also be found on the National Highways website including advice on ensuring tyres are inflated and have the minimum tread depth. Many vehicles may not have been used for several weeks over Christmas.
“The Met Office is forecasting showers and spells of heavy rain so drivers should also familiarise themselves with National Highways’ advice on using roads in wet weather.
“This includes slowing down, using dipped headlights if visibility is reduced and increasing the gap to the vehicle in front to provide more time to react.”
National Highways executive director of operations Duncan Smith said: “A small minority of frontline operational staff are involved in the PCS strikes which have had minimal overall impact so far.
“We have well-rehearsed resilience plans in place to continue managing and operating our network safely, including when wider action takes place in the new year.
“Millions of people rely on our roads and there is a possibility that they may be busier than usual on strike days, particularly as they fall on the first working days after the festive break when industrial action is also being staged on other transport modes.
“We’d urge drivers to plan ahead and check their vehicle is in good working condition.”
The agency added: “Members of PCS at National Highways have already staged three regionally focused strikes over the last month which involved some frontline operational staff – those in regional operations centres and on-road traffic officers.
“They have had no impact on the operation of motorways and major A roads.
“A maximum of around 8 per cent of staff in these roles are affected although when shift patterns and overtime is factored in the strikes affect an estimated 2 per cent of this workforce.
“The industrial action does not include colleagues in a range of other roles, including those who work on the network every day to maintain road surfaces, signs and signals.
“National Highways’ gritter fleet is also unaffected and remains at the ready to be deployed to keep roads safe and clear during cold weather.
“National Highways has already concluded its annual pay review.”