UK Driving Theory Practice Exam

Red motorway studs signify the edge of the road, which helps drivers to indicate the outer boundaries of the motorway. This is important for safe driving as it helps drivers to stay within their designated lane and maintain proper spacing between vehicles. Option B is incorrect because lane markings are usually painted on the surface of the road, not indicated with studs. Option C is incorrect as a sliproad is a separate ramp or lane that leads to or from a motorway. Option D is incorrect because motorways do not have carriageways in between them, so red studs would not serve the purpose of indicating this.