Transport was temporarily paralysed on Thika Superhighway at Githurai area on Wednesday morning after demonstrators barricaded the road.
The demonstrators, who included matatu operators and residents, erected huge stones on the roads and lit bonfires.
They demanded for the fencing of a dam near Clay Works dam which they say had turned into a death trap. This is after a 14-seater matatu recently fell into the dam, killing at least eight people on the spot.
During the protest, motorists were harassed by the demonstrators who asked for money to in order to be granted access through the barricades.
The demonstration resulted into tailbacks on the busy highway.
Matatu operators took advantage of the situation to hike matatu fare.
"The dam is now a death trap and all we want is the government to ensure that a fence is erected around it or the water be drained to elsewhere," said Ken Kamau, a local.
This was echoed by Jane Kimotho, another local who said that many lives had been lost at the dam in the last few months.
"All we want is the problem addressed once and for all. We are tired of pulling dead bodies from that dam almost on a weekly basis," she said.
She wondered why authorities were fast to demolish stalls built on road reserves but could not fence a dam.