Four prototype multimessage fiber‐optic lane control signs were evaluated for the Ministry of Transportation of Ontario to determine their suitability for freeway‐lane‐control‐signing applications. The evaluation consisted of three separate investigations, as follows. In the field test, the signs were situated and operated in an outdoor environment for approximately one year. Control instructions for cycling through each of 11 messages, varying brightness levels, and implementing a flashing mode were generated by an IBM‐PC‐compatible microcomputer using software specifically developed for this application. In the human factors test, a detailed questionnaire completed by volunteers was used to perform a statistical assessment of the visibility, and comprehensibility of each sign display. In the laboratory test, a laboratory evaluation was performed to measure various electrical and optical properties of the signs. The evaluation concluded that fiber‐optic technology can successfully be applied to lane‐spec...