Usually, the air compressors at local fuel stations and tire shops aren’t properly calibrated. After filling the air from various tire shops, I do cross-check it with a digital gauge. There is always a difference of +/- 2 or 3 PSI. Mostly some extra air is filled than the recommended tire pressure.
Reducing tire pressure on the motorway improves traction and enhances the braking power as well.
I have used a thermal gun and a thermal camera to monitor the temperature of tires while traveling on the motorway (M2) during the summers. Based on my personal experience and knowledge, I will recommend reducing the tire pressure by at least 2 PSI to get better traction, handling, and braking power.
I will highly recommend everyone buy a reliable digital tire pressure gauge to check their tire pressure before traveling on the motorway during the summer.