visually average speed computer and recorder is my favorite unit ppro and thanks for the back up...vascar...puts out no signal at all, and I used to use it while moving most of the time, but it works very well up on entrance ramps...ever see those white lines painted across the road, or a set of orange cones sitting alone side the road for no reason...usually a 1000' apart...you can do this with a stop watch as well if you have these predetermed points already set up...that's all there is too it....detector is useless...just got to know what to look for along the road...