Too high pressure in the lorry tyres:

The question is about the effect of too high tyre pressure in a lorry on the braking distance. Too high a pressure may make the braking distance longer - the answer is B.

The Regulation on the technical conditions of vehicles requires the tyre pressure to match the values recommended by the manufacturer. A tyre inflated above the standard becomes hard and bulges in the middle, so it touches the roadway with a smaller area - and a smaller contact area means less grip. The vehicle brakes less well, skids more easily on a wet surface and bounces more on bumps. That is why it is not true that the braking distance becomes shorter (answer A) or does not change (answer C). You check the pressure when the tyres are cold, according to the manufacturer's table, and you take the vehicle's load into account - an empty lorry and a loaded lorry may need different values.

Legal basis: § 11 para. 5 of the Regulation of the Minister of Infrastructure on the technical conditions of vehicles and the scope of their necessary equipment; Art. 66 para. 1 point 1 of the Road Traffic Act (Prawo o ruchu drogowym)