Big plans to transform the Mandai area into a 126ha nature precinct by 2023 would have to include better ways to get there as transport options are now very limited.
Only two daily bus services, 138 from the Ang Mo Kio bus interchange and 927 from the Choa Chu Kang bus interchange, currently serve the Singapore Zoo and the surrounding Mandai area.
They take about one hour to arrive at the zoo.
Another service, 926, from the Marsiling and Woodlands MRT stations, the closest to the zoo, operates only on weekends.
An express bus service operated by Bus-Plus Services, a wholly owned subsidiary of SMRT, began a four-month trial run last Saturday and facilitates access from Bedok, Tampines and Sengkang, but it operates only on weekends and selected public holidays.
Basically, there is no convenient way of getting to the zoo without driving or taking a taxi, said Ms Zaitoon Bivee, who has taken her two-year-old son there by car four times.
"There should be express buses from different areas or free shuttle buses every 15 minutes from the nearest MRT station," said the 42-year-old adjunct lecturer.
Announced on Wednesday, the Mandai nature precinct will comprise the Singapore Zoo, Night Safari, River Safari as well as the Bird Park, to be relocated from Jurong, and a new Rainforest Park, where visitors can walk along aerial walkways that stretch from the forest floor to treetop canopies.
Conceptualised for eco-tourism, it will have eco-lodges where people can spend the night, as well as free nature trails, boardwalks, outdoor seating and playgrounds.
First announced by Prime Minister Lee Hsien Loong in 2014, the redevelopment of the area is being overseen by Mandai Safari Park Holdings, a wholly owned unit of Temasek Holdings which is chaired by former Temasek chairman and Cabinet minister S. Dhanabalan.
The first phase of development, which is expected to begin later this year, will cost $1 billion.
Last year, the zoo hosted 1.7 million visitors, and the two safaris had about a million visitors each.
National University of Singapore transport researcher Lee Der Horng agreed that public transport to the zoo is currently "extremely poor".
He contrasted it with the Taipei Zoo which, although located about 10km away from the city, is easily accessible by a metro station directly outside the zoo.
Dr Lee said a "branch line" of the MRT could be built specifically to serve the eco-precinct, adding that autonomous vehicles could be used to ferry visitors within the nature precinct.
Ngee Ann Polytechnic senior tourism lecturer Michael Chiam said extending the MRT line may not be feasible. "Since it is not a residential area, the authorities would need to study whether it is financially viable to extend the MRT line to Mandai," he said.
He suggested that the eco-precinct be connected to the Park Connector Network to facilitate cycling into the area and that the authorities could study demand for buses, increasing the number and frequency of services as necessary.
The group chief executive of Mandai Safari Park Holdings, Mr Mike Barclay, said it is taking suggestions from the public on the rejuvenation of the Mandai area and exploring a "range of options" with the authorities to improve accessibility to the area.
"These include introducing shuttle buses from the upcoming Springleaf MRT station and direct bus services from key regions that are otherwise not well connected to Mandai," he said.
Located along Upper Thomson Road about 8km away, the Springleaf station on the upcoming Thomson-East Coast Line is slated to be completed in 2020.
Also under consideration are shuttle buses and trams to move people between the east node, where the existing attractions are located, and the west node where the new Rainforest Park and the relocated Bird Park will be situated.