From transit link website:
Bus 858: Estimated traveling time from Yishun mrt to Changi
Airport mrt: 70 mins
Bus 969: Estimated traveling time from Yishun mrt to Tampines
Interchange: 64 mins
But, if you look at the bus routes of both buses, it really
doesn’t justify the estimated traveling time taken from transit
link website.
From memory, both buses traveling time from yishun mrt to the
designated locations is definitely shorter than the estimated time
from transit link.
Maybe their estimated timings for both buses are taken using the
slowest bus driver.
it seems like bus 969 is a better choice given that the transfer
from the shuttle service has its waiting time, whereas waiting time
for MRT from Tampines to Tanah Merah will be shorter, i think. The
risk of getting a traffic jam of 858 is higher than 969 as it
travel on 3 expressway and 969 travel on 2. i think i have my
answer, thanx, just hope morning traffic is not that bad.