the Flashing speed sign is there to let you know what your speed is. The photo ones have a van setup wth an actual person sitting there. This is one from the "private" company contracted to increase revenue. The photo radar ones only want your money and do not carry any points against your lic. The ticket writing construction zone are either county, city or the CHP pulling you over then politely handing you a ticket for approx $200 or more + the magical 4-6pts you just won.