Kind of puts me in mind of an situation back in the '80s when Volvo decided to make the sidelights on their cars be on whenever the ignition was on.

They did this as a consequence of a law change in Sweden that required all vehicles to switch their sidelights on when moving. That law came about as a consequence of the fact that in a large part of Sweden has 3 months or so of 24 hour twilight/darkness each year, which meant that laws written in terms of "Vehicles shall switch their lights on 'at night' or 'after dark'" etc. were always open to legal (mis)interpretation.

Later, when drivers in other countries drove their Volvo's around during the daytime, (besides getting perpetually flashed "Your lights are on idiot!", by other road users taking the p***:), they found themselves in court if a sidelight bulb blew--EVEN IF IT WAS BRIGHT SUNLIGHT.

Laws, like rules, are written to achieve a particular end. In this case, the lights are there to ensure the vehicle can be seen in low-light visibility.

The law is an ass because often as not, there is no room allowed for interpretation. To be seen at night, the vehicle must have lights. To do any good, the lights must work. If they don't work, an offense has been commited.

If the working light would not have affected the visibility of the vehicle, should the errent owner be prosecuted?