Kenya Railways has released a presentation on the Standard Gauge Railway master plan and the progress Kenya has made in construction.
The plan was summarised in a map that shows the paths the railway will take and its alignment through Nairobi National Park.
Managing director Atanas Maina also outlined measures taken to mitigate impact on animals and the environment.
These include bridge pillar foundations, abutments, noise deflectors and a fence enclosing the construction area.
Regarding human-wildlife conflict, Maina said the movement of construction equipment and road vehicles will be restricted within the fenced-out working areas.
A section of conservationists said the construction of the Nairobi-Naivasha railway through the parks would drive away animals.
Concern also arose from several incidents of animals straying out of the park into residential areas.
Maina said on Wednesday that the SGR will cost taxpayers Sh2.02 billion more. The 120km route had been estimated to cost approximately Sh150 billion.
He said the cost went up after the original route was modified as demanded by conservationists.