Do all road traffic regulations require to be the same across the UK? No, of course not. The nature of the road network in more densely populated England with its major motorway network makes it so. That said, there’s good reason why harmonisation in many aspects was and still is coming in across Europe, whatever Brexiteers may say.
Certainly, in road haulage, load weights for transportation across jurisdictional boundaries and vehicle design and safety requirements direct it, even if national interests can still override them. As Justice Secretary I brought in a lower drink driving limit. Actually, moving Scotland towards the almost European standard and leaving England and Wales as an outlier was the right thing to do. I also look forward to the day when England catches up with the rest of the continent not just Scotland and until then crossing the border sees different rules.
But there’s an area where I do believe harmonisations now called for. The HGV speed limit was increased south of the border in 2015 to 50mph and 60 mph on single and dual carriageways respectively. In Scotland it remains at 40mph and 50mph except on the A9 where the English limits apply.
Now anyone who travels on that latter road knows how much it has improved but it’s not just the dualled parts but the speed limit for hauliers that has made it so. Frustration being stuck behind a slow-moving truck was a regular cause of accidents if not fatalities.
No one would seek to lower the speeds on that highway but why can’t other trunk roads be increased to match it. Issues remain on the A1, A77 and so on. Lorries require to slow down when crossing the border and frustration for other users increases.
Studies by the Department of Transport have shown no increased accidents from the higher speed down south. There’s no need for average speed cameras to be introduced unless road safety dictates it. Environmental arguments tend to mitigate towards reducing congestion and slow-moving trucks. Haulage and motoring organisations support it.
If it causes the Scottish Government any concern, just view it as harmonising with the A9.