In Denmark, several municipalities have hired garbage-collection trucks to test mobile coverage (danish article with images at https://www.dr.dk/nyheder/regiona

In Denmark, several municipalities have hired garbage-collection trucks to test mobile coverage (danish article with images at https://www.dr.dk/nyheder/regionale/oestjylland/skraldebiler-afsloerer-skidt-mobilsignal-paa-djursland https://www.dr.dk/nyheder/regionale/oestjylland/skraldebiler...) and some utility companies have done the same with recievers for short-range transmitters placed in water/power/heating meters.