The South African National Roads Agency Limited (Sanral) is warning road users to expect delays on the R21 between OR Tambo International Airport and Pomona road in the northern and southern directions from March 17, to the expected completion date of May 13, owing to planned routine road maintenance. The work, which will be undertaken from 09:00 to 15:00 every day, will include patching of the existing road surface, sweeping and cleaning the road surface, deviation and control of traffic vehicles and the reinstatement of road markings.