Lidar, aka lasar has to be shot in a straight line (true ^), and close, so usually under 1/4 mile away. They have to aim at something on your bike that is parallel to the ground, on a car that's a license plate, but on a bike, it's much harder to nail us, b/c we are smaller. It's possible, especially if you are solo.
Almost always, when I've been tagged (even in my car), it's under 1/4 mile, so usually you should see the LEO. but yeah, it's instant on. you need a laser jammer if you are going to evade.
I'd say radar, gives you minimum 10 seconds to adjust your speed at freeway speeds. and I'd say it takes them 5 seconds to get a good read on you with radar.