@mukiha, I think you are wrong to a great extend.

One,the police do a good job,they open the road with more traffic and clear exit for longer than the road with less traffic or a jammed exit. In the developed world,cops regulate the timings of traffic lights during peak hours from a switch board. You simply can't program that on the busiest of roads.

Two, the roundabouts creates unnecessary delays negotiating. They should be replaced with cross junctions,especially the ones on uhuru highway. Take the Kenyatta avenue/uhuru highway roundabout.
If you open uhuru highway both ways,from university way and from haile selasie,stopping the inner most lane [for turning right] hence releasing the ones proceeding straight and those turning left,with the roundabout,you have to negotiate that semi circle before proceeding. Now compare that with cross junction. On the latter, you would just drive straight saving the time you would have lost negotiating the roundabout curve and achieving higher speeds.. Now picture when releasing all cars turning right,you have to negotiate three quarters of the damn roundabout, how much time is lost? Compare that to just turning right.

Roundabouts should go, there is a reason why you don't see them in most of the developed world.

Before proposing the removal of the Uhuru/Kenyatta roundabout {NB: for those who don't know what a pun is, that was a nice example!} please walk 50m east to the Kenyatta/Koinange cross junction and observe the chaos!

And here is a bit of history: in the early 1980s, the Car&General junction was a cross with traffic lights....chaos every day and we had much much fewer cars. The a bright traffic engineer at city hall converted it into a roundabout and removed the lights...problem solved...to this day, i might add!