All forces have to publish where they are going to be in advance. Here is the NY Police's Deployment page
HERE
This weekends site info quoted below, but it's just all the usual spots they have cars around at anyway;
"North Yorkshire Police will be carrying out mobile safety camera enforcement on the following roads between Friday 1 July and Monday 4 July 2011.
A64 between Scarborough, Malton and York
A171 Whitby to the Cleveland border
A171 Scarborough to Whitby
A169 Pickering to Whitby
B1257 Helmsley to Stokesley
A 1237 York outer ring road
A64 Hopgrove, Tadcaster
Beckfield Lane, York
Tadcaster Road, York
Malton Road, York
B1228 Grimston Bar, Elvington
Huntington Road, York
Millfield Lane, York
Strensall Road, York
Stockton Lane, York
Please remember that in addition to speed, the camera can also capture mobile phone and seatbelt offences.
The mobile safety cameras will be in operation at the above sites at various times during the dates stated. Cameras will not be in use on the above routes all day, every day. The above locations were accurate when this page was first published.
Due to operating constraints at some of our sites, our mobile safety camera locations may change on occasions without prior warning."