Page "M25 motorway" Paragraph 8

Much of the M25 is lit to help reduce accidents.

The current illuminated sections are from Dartford to junction 3, junction 5, junctions 6 to 21a and junctions 23 to 31.

The type of lighting varies.

Some sections use the older yellow low-pressure sodium ( SOX ) lighting while others use modern high-pressure sodium ( SON ) lighting.

Some stretches have recently been upgraded to SON lighting.

These include Junction 5, junctions around Heathrow and Junction 27.