Traffic sensing

["Neil Ball" <neilball@xxxxxxx>]

Hi to the group

I need to install a "traffic" sensor on a driveway that can
distinguish
between traffic arriving or leaving the drive. I remember some posts a
while
back that discussed such sensors, so can anyone comment on the systems they
have used or know of (with links to suitable manufacturers/suppliers web
sites if possible).

I'm looking for simple volt-free contacts from the sensor to allow me to
integrate this with alarm and lighting systems already planned.

Regards

Neil B.