'Tis the season for flat car batteries, according to transport commentator Conor Faughnan.
Today will be one of the busiest days of the year for breakdowns.
Most people will be returning to work on Tuesday after the Christmas and New Year break.
Conor told Breakfast Briefing a lot of people simply won't have driven their cars until today.
"It's a bit like the mother of all Monday mornings, isn't it, the first day back after Christmas," he said.
"Roads this morning are likely to be busy - we'll see the start of a commuter pattern which we haven't had for the last couple of weeks.
"The other thing that will catch a lot of drivers out this morning [is] there's a lot of cars that are parked up and haven't moved for a week or so.
"It'd be unsurprising if you get a lot of flat batteries in cars refusing to start this morning".
He said drivers should have been starting their cars before now.
"As a general rule: if the car is going to be idle for a period, it's worth starting it and taking it for a short run.
"If you know if you're not going to use your car, or not going to use it much, for a week, 10 days, two weeks it's a good idea halfway through that period to start the car before that period and give it a short drive.
"That's particularly true in the middle of winter when it's bitterly cold, because actually there's greater demand on car electrics in cold weather - it takes more power to start a car.
"First day back, post-Christmas, is statistically the day when it's most likely to catch you out.
"I'd say lots of cars won't start this morning, that's kind of a normal pattern as we get back to work".
Vulnerable road users
Conor said there is a particular onus on drivers in darker mornings.
"We've got to be very careful of vulnerable road users - these are pitch dark mornings of course, the darkest time of the year," he said.
"You'd worry in particular about people on e-scooters, people on bicycles and pedestrians.
"There's a danger to vulnerable road users, but there's a greater responsibility for car drivers - particularly this time of year".
He said cyclists should "light up - please be seen."
He has these top tips for people taking to the roads.
"A little bit of extra time to do your journey, perhaps not so much this morning," he said.
"There'll be some stragglers, we won't have everybody on the road, but perhaps by Monday of next week things will be back to their full level of congestion.
"Likewise if you are a cyclist, or you're using an e-bike or something of that sort, we'd advise people to take it slow and handy.
"Make sure you're properly illuminated and don't take risks".
Conor believes it will be a busy day for car assistance companies.
"I suppose you could say 'tis the season for flat batteries - that'd be the one that you'd notice.
"Statically, it will be one of the busiest days of the year for car breakdowns," he added.