LRT to go over or under the Don River?

[attach]5232[/attach]How do you get a light rail transit line across the Don Valley?

Build a bridge, say transit officials.

It’s one of the options being considered by provincial transit agency Metrolinx in light of a revised plan for the Eglinton Crosstown light rail project that is now intended to travel only underground, from Black Creek Drive to Kennedy Station.

Transit officials have been looking at ways to overcome the planning hurdle that is the Don Valley ever since the province and Mayor Rob Ford inked a new deal last year that would see the 25-kilometre line mimic a subway. The original plan, created under the now-defunct Transit City, was to operate light rail underground only along the midtown portion of Eglinton, from Black Creek Drive in the west to Laird Drive in the east.

Now faced with the prospect of steep valley grades east of Brentcliffe Road, Metrolinx vice-president Jack Collins said engineers are currently researching alternative plans to build an at-grade bridge that would travel parallel to Eglinton, along the south side of the thoroughfare and above the valley.

However, the possibility of tunneling below the Don Valley has not been ruled out, Collins said.

“It’s feasible, but it’s more expensive,” he said.

Keeping costs down is a huge consideration. Collins said the requirement of additional underground stations, and a revised environmental assessment, among other costs, has driven the project’s price tag up about $2 billion, to an estimated $8.2 billion.

Area councillor John Parker is in favour of having the line travel across the Don Valley, rather than below it.

The Ward 26 rep says he’s been a proponent of having the line travel above ground — “where God intended LRTs to be” — since Day 1.

“I’ve always had my doubts of the logic of putting it underground in the eastern end,” he says.

Parker, who also sits on the TTC board, says tunneling below the Don Valley along Eglinton presents a practical engineering challenge.

“The track would have to be built with a slope gentle enough to accommodate the limits of traction that a steel wheel will have on a steel rail,” he said.

Additionally, Parker says subterranean travel on that stretch of land is unnecessary. While it makes sense to bury the line in midtown Toronto to avoid street congestion, Parker says, the stretch along Eglinton east of Brentcliffe doesn’t have many cross streets, and it’s fairly vacant, making it ideal for above-ground light rail.

“We’re buying LRTs and asking it to do what a subway does,” he said. “It’ll be the goofiest LRT line known to man.”

Parker says he expects these concerns will be raised as a revised environmental assessment becomes subject to public consultation and council scrutiny.