The N1 South-bound between the Flying Saucer Interchange and Botha avenue on the N1/R21 will be closed from 23:00 on February 6 to 04:00 on February 7 to allow for geotechnical investigations required for the rehabilitation of the N1 sinkhole near the Flying Saucer Interchange in Centurion. Only one lane will be open during this period.