TransLink says a proposed SkyTrain extension connecting Surrey and Langley along the Fraser Highway would cost an estimated $3.12 billion, nearly twice the estimated cost of connecting the two areas using light rail.
That's also up from the SkyTrain project's estimated $2.9-billion cost in 2017.
According to CEO Kevin Desmond, about $1.6 billion of the required money is currently available.
The transit provider also provided a first look at the proposed stations along the Expo Line extension: 140, 152, 160, 166, 184, 190, 196 and 203 streets. Those eight stations would require 55 additional SkyTrain vehicles.
"Our mayors recognize that we need to improve transit in this region," Desmond told reporters Friday, citing the rapid population growth in the area.
The entire extension is expected to carry an annual operating and maintenance cost of $32.4 million and an estimated fare revenue of $21.3 million in 2035.
TransLink said the average bus ride along that route currently takes about 50 minutes, adding that the proposed SkyTrain project would reduce the travel time to just 22 minutes.
The transit provider is predicting a ridership of 62,000 people a day by 2035 and 71,200 by 2050.
In an effort to reduce initial costs, TransLink said it is also putting forward a two-stage option, with the first phase only extending as far as Fleetwood or Clayton.
The latter would cost an estimated $2.22 billion and require five stations and 35 vehicles.
A seven-kilometre first phase to Fleetwood would only cost $1.63 billion and require four stations and 25 vehicles.
Desmond said those options all present a strong benefit-to-cost ratio, but extending the timeline for the entire extension would increase costs.
Former Langley Mayor Rick Green says the plan is a waste of taxpayer’s money.
"There's no end of tax dollars I guess, if you want to start taxing everybody for everything, but people are getting tired of it" Green said. "Why aren’t we starting to be responsible with our money?"
The announcement comes eight months after a controversial Surrey City Council decision to scrap a $1.65 billion plan for the Surrey-Newton-Guildford LRT in favour of the 16-kilometre extension.
But a TransLink survey released back in May found overwhelming support for the SkyTrain extension, with 90 per cent of those living in Langley and more than 80 per cent of respondents living in Surrey agreeing with the project.
Desmond said the update to the proposed plan will be presented to the TransLink Mayors' Council next week.
According to TransLink, public engagement on the project will begin in the fall. If approved, construction on the proposed project would start in 2022 with service beginning in late 2025.
TransLink said it's also planning a screening process that will consider how the project could affect the environment in the region and will consult First Nations partners.
Green is concerned about the impact to the Serpentine River and the Green Timbers Forest.
"They’re going to have to clear-cut a good chunk of forest on either side of Fraser Highway," he said.
TransLink says protecting vegetation in the area will be a priority, adding that an elevated SkyTrain track would have less of a footprint than a light rail line that runs along the ground.
With files from CTV News Vancouver's Regan Hasegawa in Surrey
