In general, more frames means more 'shots' at getting a good image. See: Frame Rate Guide for Video Surveillance.
That said, if the cars are going slow (I'll interpret this as 10mph or less), I doubt 30 or 60fps will make any difference.
The shutter speed will though. Make sure the camera lets you set at a maximum shutter speed of something like 1/250s or 1/500s so you can ensure there is no blur.
FWIW (and I haven't done a *ton* of LPC setups) you want 1" or less of vehicle travel during the exposure period.
EG: 10MPH = 176 inches per second. To get reliably good images for vehicles travelling at 10MPH you would want a shutter speed around 1/176th of a second. This of course isn't a standard value so you'd want to round up to the next highest number, probably 1/200th or so.
60fps could result in a shutter as slow as 1/60th of a second. Giving you the ability to capture plates up to a speed of about 3.4MPH.
I don't think 60fps will give major benefit over 30fps, you need a camera that's capaable of a relatively fast shutter.
Unfortunately there is no way to set the shutter speed in the menu on this camera. The spec states the range of the shutter speed is 4/25s~1/45,000s but they give no way to adjust it that I can see.
Also is there any point in having the camera set at 60fps if the recorder can only record at 25fps?
Unfortunately it appears that the people at Dahua think that allowing us to set the shutter speed is a bit advanced for their PAL customers.
I have checked 3 different models of Dahua HD-CVI 720p cameras and none of them allow me to adjust the shutter speed in the OSD menu.
The “Exposure” settings / choices are:
None of these have a sub menu to allow further adjustment.
Below is a snap from their manual on OSD settings.
Does anyone else have a different experience using PAL versions HD-CVI 720p?