It's cold and by all accounts it will be getting colder. It's the time of year when dark skies and cold weather make commuting more time-consuming and more dangerous. I think it's a good idea to speak to each member of your team about leaving a little earlier, driving a little safer, discussing where they park and ensuring they wrap up warm.
Some may see this as condescending but I think it's caring and shows some interest and compassion. Making sure that all your team are safe and well is a good start to every day.
The way you carry this out is entirely up to you - be it a team thing, a one-to-one or an internal email, I think the short amount of time taken to do this will make a difference to all.
Just a short note today, inspires by the weather!