Advice from the Londoners please?

[JayDub]

On the 14 Oct - a Friday, which route would be safest to get us (by car)from Smug Oak Ln, Bricket Wood to Watford, Warner Bros Studios for 12:10 pm? and how much time should I allow?... I'll ignore the M25 route? I was intending to use the A405.
https://www.google.co.uk/maps/dir/Smug+Oak+Lane,+Bricket+Wood,+St+Albans+AL2+3PN,+UK/Watford+WD25+7LR,+UK/@51.7020571,-0.4041228,14z/data=!4m19!4m18!1m5!1m1!1s0x48763fbf01880a63:0xfa0ca46014f9bdec!2m2!1d-0.3523011!2d51.7065448!1m5!1m1!1s0x4876402e53ad7ec3:0x59a5d84a9308f851!2m2!1d-0.4181283!2d51.6910752!2m3!2b1!7e2!8j1476266400!3e0!5i1

[London_Phil]

Going on the Harry Potter Tour eh?
Both my cost centres went to a very local school, and they had the Harry Potter bus as a school bus many times

Either route will be fine, shouldn't be too bad that time on a friday.

Its VERY well signposted, so youll be fine, but its London, so well nick your wallet anyway     

[JayDub]

but its London, so well nick your wallet anyway     

Yup, and Harry has the contents of my wallet now anyway, Cheers Phil.