Crossing Mitcham Common on dipped beam
Mitcham Common is around 460 acres of open land with the A236 Croydon Road running across it, and that stretch feels faster and more open than anything in the town centre, so speeds creep up between junctions. At night it is also one of the less brightly lit roads you will use regularly, with the Common on both sides and little in the way of frontage to spill light onto the carriageway. A beam with a clean cut-off makes that drive straightforward. A scattered one makes it hard work.
The same is true around Cricket Green and Cranmer Road, where cricketers cross the road between pavilion and pitch, and on the approach to Mitcham Junction where Carshalton Road narrows over the railway and tram lines. Those are places where you need to pick out a person or a cycle at distance rather than at the last moment. A yellowed lens cuts usable output substantially, and because it happens over years rather than overnight, most drivers never register the loss.
Town-centre driving hides the problem. With the Fair Green stretch of London Road open only to buses and cycles, general traffic uses the one-way system, and all of it is lit and slow. Meanwhile the cars themselves sit parked on the street in Victorian and interwar terraces with parking on both sides, taking sun all summer, which is what degrades the outer hard coat in the first place. From around five to eight years of age the yellowing usually starts to show.
We check whether the fault is outside the unit or inside it, because condensation, a peeling reflector or a crack means restoration is pointless and we will say so. If the surface is the problem we mask the car, wet sand through the grades, machine polish, apply a UV-stable clear coat and then check the beam pattern and aim. The run in is London Road to the Cricket Green, Cranmer Road to Carshalton Road and south into Hackbridge, about eight minutes.