More information from LTA website regarding traffic controls during F1 period :
"6 Besides the single-lane, motorists can also enter the area via Temasek Boulevard from the ECP slip road to Rochor Road throughout the day.
7 However, if traffic volumes are unusually high, access via these two routes will be regulated, depending on prevailing traffic conditions.
8 While driving along these roads, motorists are strongly advised not to stop their vehicles indiscriminately so as not to obstruct the traffic flow. Traffic wardens will be deployed on site to direct traffic and assist the public. Road information and directional signs will be put up in the vicinity to direct motorists.
9 Please refer to Annex A for more details of roads that will be affected by the road closures and the different ways of entering Marina Bay.
Public Transport Arrangements
10 More than 400 train trips will be added on the three race days to meet increased demand with train operating hours extended until 1am.
11 Operating hours for selected feeder bus services will also be extended to match the last train service during the three race days.
12 Free shuttle buses are also available between the Lavender MRT station and Gate 1 at the Race venue. After the race, taxis will be an additional mode of transport."
More information available here:
http://app.lta.gov.sg/apps/news/page.aspx?c=2&id=dba5decc-68d2-4024-b72a-192caf159436