The holding of a database and acting on the info held is absolutely fine - think about the AA or whoever issued the Road Atlases with the info printed in them - as you are simply using a GPS device to plot your position relative to that of the 'Accident Blackspot'..
The difficulty and problems arise due to 'reading' or interfering with the transmitted signal from the speed detection device and reacting to the fact that the device is there. You know what its for and adjust your speed accordingly if required.
Think about those black and white films you see on TCM of cops and robbers. The robbers monitor the police radio frequency and react to info received or jam the frequency so the Cops cannot speak in order to evade detection. The analogy remains the same regarding speed detectors/jammers, even though your not on an Italian Job type run......
HtH
B