It will surely be extremely distracting to the driver/ operator and therefore a somewhat counter-productive safety measure. The beacon could be mast or roof-mounted perhaps?

Under the Artificial Optical Radiation regs, which came in last year you need to carry out a risk assessment to identify any risk to staff caused by light sources. The risk mainly depends on the intensity of the light and its frequency. You say this is a high intensity light, how intense is it? A very strong beam could cause significant damage, especially if it was strobing. Eyes natural react to intense light sources (aversion reflex) but a strobing light source might defeat this reflex. Do you need this light or can you put up a simple shield to block it? Failing that look at some sort of eye protection. Have a look at this http://www.hse.gov.uk/ra...onionising/aor-guide.pdf for more information or get in touch with the HPA who wrote this for the HSE.