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.
The project will be completed in two years at a cost of Sh2.3 billion.
The Chinese-built railway began commercial operations on January 1.
Slow approvals of Public Private Partnerships usually puts off high quality investors.
The project is expected to gift Tanzania with its first high-speed railway.
An elevated railway will run 6.7 kilometres across the national park perched on giant pillars.
Talks are underway for China to fund a new highway and rail extension.
The Chinese-funded Orpower 22 power plant will take 17 months to complete.
Bedsitters will rent for Sh3,200 per month on a 30-year rent-to-own plan.