Looop will execute the plan, while the county government will provide the land.
Construction of the cable cars system is expected to begin in December.
The 77 kilometre road will be upgraded from gravel to bitumen standard.
The much-awaited 2km-viaduct still remains a project without a launch date.
The Chinese are using the hanging basket technique to tackle challenges.
Work was expected to begin by end of this month and tenders had already been floated.
Rising costs of roads rehabilitation is becoming a huge burden to the government.
The firm was picked from a group of eight companies that were in January invited to bid for the work.
Sinohydro Tianjin Engineering Limited will install the footbridges at a cost of Sh880 million.
Chinese engineers are racing to complete the the project by June next year.
Developers will be allowed to build up to 75 floors in high-density areas.
The much-awaited summit will take place on June 12-13, 2025.
All development applications will now require residents' approval.