sentences:  M16 motorway
  
  The M16 motorway was the designation planned in the late 1960s and early 1970s for use on Ringway 3, a new motorway planned as part of the London Ringways Plan to run a circular route around London.Construction of the first section of the M16 began in 1973 between South Mimms and Potters Bar in Hertfordshire and opened in September 1975 with the temporary general purpose road designation A1178.