Should you obey section 72 of the Highways Act 1835? This is a question drivers ask themselves (I'd assume in most cases unconsciously) every day. The act imposes a penalty for "wilfully rid[ing] upon any footpath or causeway by the side of any road made or set apart for the use or accommodation of foot passengers". We can all agree that, in normal driving conditions, we should obey the law and avoid mounting the pavement. However, if it meant avoiding a child who had jumped out into the road, most of us would break the law without a second thought.

Autonomous vehicles will soon be placed before that same decision, yet how they should react is widely disputed. Some developers have argued that a self-driving car should never swerve if it meant breaking a road rule. Braking should be considered enough to discharge any duty of care towards a pedestrian. They compare this to a tram - you wouldn't expect it to swerve off the tracks if someone jumped in front of it.  

This seems to me to be a wholly unsatisfactory position, so it is welcome that the Law Commission has published an (easily digestible, 212 page) consultation paper into the law governing automated vehicles. I recently wrote that the solution to some of the dilemmas that programmers of self-driving cars face lies in attempting to forge a social consensus on how these cars should act. It is important that drivers, pedestrians and law enforcement are aware and have the right expectations of how autonomous vehicles will fit into the traffic system.

The Law Commission make the helpful proposal of developing a digital highway code. This may include identifying situations when autonomous vehicles are allowed to break the law. After all, some human behaviour that "breaks the rules" is tolerated. So why should robots be treated differently?