Some have sophisticated equipment mounted on airport vehicles to check conditions
And in the parts of the world where we experience winter conditions etc often,
ALL airports with ATC or AFIS/FIS have one........ :
We use it all the time in the winter, after the runway has been swept, and when we (ATC) think it is warranted. (I a pilot reports report less BA then we have reported etc)
The car (A Saab 9-5 Estate here at Bardufoss/ENDU) often do testruns inbetween landings, when the aircraft lands, the car starts the run following the aircraft down the runway. A return run has to be made, in all it takes about 5 minutes. You need about 15-20 miles spacing on final to get a testrun in between.
(2443 meter rwy)