A major traffic snarl-up paralysed movement along the Nairobi–Nakuru Highway on Thursday night, forcing authorities to announce alternative routes for stranded motorists.

The Kenya National Highways Authority (KeNHA) said the gridlock began around 8:30 p.m. between Naivasha and Kikopey. The situation was worsened by drivers ignoring lanes and an unusually high number of vehicles returning from Gilgil, where a National Youth Service (NYS) pass-out parade had drawn large crowds earlier in the day.

“The Authority regrets to bring to the attention of the public that from around 2030hrs yesterday, congestion developed along the Nakuru–Nairobi Highway. This was worsened by lane indiscipline, which resulted in a traffic gridlock that is currently being experienced between Naivasha and Kikopey,” KeNHA said in a statement.

To ease pressure, KeNHA advised motorists to use two alternative routes. Those travelling from Gilgil were directed to the Gilgil–Olkalou–Dundori–Lanet road, while drivers leaving Nairobi were urged to take the Flyover–Njambini–Olkalou–Dundori–Lanet route.

Traffic police were deployed overnight to help restore order. Officials urged drivers to remain patient and avoid overlapping, which often worsens gridlocks. “Motorists are urged to observe lane discipline and avoid overlapping, as it will make it impossible to ease the congestion,” KeNHA noted.

By early Friday morning, the agency said traffic was expected to improve gradually, though it warned that heavy volumes could persist for several hours.

The Nairobi–Nakuru Highway is one of Kenya’s busiest roads, linking the capital to the Rift Valley and western parts of the country. Frequent congestion on the route has long fuelled calls for faster expansion and stricter enforcement of traffic rules.