As a surgeon specialising in trauma, I see what excessive speed does every day. It kills. It’s claimed 67 lives so far this year in NSW. It maims, it destroys families, it decimates communities. Yet, it is avoidable.

On average, 32 people are seriously injured every day on NSW roads. I treat them. I meet the families of those who have died.

If the promises made by both parties in the lead up to Saturday’s election are implemented, the road toll will only get worse.

The decision by both parties to back an increase in the speed limit on the WestConnex motorway from 80km/h to 90km/h is venal and reckless.

The NSW government promised this if they were re-elected, and undertook to review 80km/h speed limits on other roads. And the opposition followed suit. Both parties clearly value your vote more than your life. How can the paltry two-minute saving in travel time that the premier touted justify this change?

As a surgeon, I fully appreciate the horrific injuries sustained by survivors of crashes at speeds greater than 70km/h in current five-star safety rated vehicles.

The human body has evolved to survive impacts at 30km/h. As speed increases, there is an exponential increase in the energy available to damage the human body.

Physics shows, driving at 80km/h is the same speed a vehicle would reach at ground level if it drove off the roof of a six-floor building. At 100km/h, it is like driving off a 10-storey block.

Humans are poor at judging risk, reaction time is finite, and stopping distances increase exponentially as speed increases.

We all make mistakes. That is why a safe system must provide for the fallibility and fragility of humans using the road system.

Driving at 80km/h, it takes the average person 85 metres to stop on a wet road, and at 90km/h, it takes 103 metres. Those extra metres can make all the difference. At 100km/h it takes 122 metres to stop.

The current speed limit of 80km/h on WestConnex, particularly in its tunnels, reflects balanced considerations by technical experts within Transport for NSW who determined the safest speed limit for that situation.

In the bid to win votes, politicians want to override the road safety experts. They are making a mockery of current campaigns to reduce fatalities caused by speeding. “Every K counts” is based on evidence that most speeding deaths occur at no more than 10km/h over the speed limit, which many people thought was safe.

Tunnel crashes, similar to the Burnley Tunnel inferno in 2007 where three people died, carry a huge risk. Following the fire, the Victorian government lowered the speed limit from 100km/h to 80km/h and introduced speed cameras. Since then, they haven’t had another fatality.

As someone who was privileged to have been involved in a review of the failures of the previous decade of the national road safety strategy to reduce fatalities and injuries, I have been appalled at a range of populist policies recently proffered in NSW.

It seems we are going backwards. Specifically, the reintroduction of portable signs associated with mobile speed cameras, the offer of early return of demerit points, and now the appalling spectre of increased speed limits on major motorways.

Research in the National Road Safety Strategy found the best way to reduce deaths and injuries – and encourage safer driving – was to maintain an element of randomness in camera deployments, without signage.

NSW is out of step with current research. The World Health Organisation and OECD research also supports the use of mobile speed cameras without portable signage. Portable signage limits the effectiveness of a safety camera program and reduces effective general network deterrence.

Queensland and Victoria deploy covert as well as unconcealed mobile speed camera (MSC) vehicles, with limited or no signage, and the number of infringements issued in these jurisdictions is many times higher.

The quest for votes should not trump the right of all road users to arrive safely after every journey.

John Crozier Dr John Crozier is Chair of the RACS bi-national Trauma Committee. In 2017/18 he co-chaired the Federal Government Inquiry into the National Road Safety Strategy 2011-2020