Is it illegal to back out onto a main road?

While it’s not illegal to reverse out of a driveway onto a main road, it’s not advisable. Reversing into the driveway is a better option as you control the traffic flow behind you on the busy road. However, the safest option is if you can turn around in the driveway.

When reversing out onto a street, you need over twice as much time as pulling out forwards. In busy traffic, it could mean that there is just not a sufficient gap for you to do this safely without another motorist being courteous and letting you in. Performing this manoeuvre could cause other vehicles to brake or try to swerve around you, meaning they change lanes. It all increases the risk of an accident.

When reversing you have bigger blind spots which put cyclists in more danger.

You must not reverse around a corner from a side road into a main road. The Highway Code is very specific about this: Do not reverse from a side road into a main road. When using a driveway, reverse in and drive out if you can.