M25 specs from chorleywood to ?

[Furyous]

Chaps
.
I'm off to goodwood saturday and planned to use the 25 from chorleywood and down.
Just crossed the motorway and I see there are specs cameras in use.

Anyone know how many junctions or miles these specs HP on for?

Trying to calculate my timings to get to goodwood for 8.

[cwoodsie2]

Down to just south of M40 junction (16)

very dull!

[Furyous]

Ah, cheers for that, shouldn't make to much difference to my timing?

[SVTRick]

Or should your front index plate fall off.....