As tight spots go, the stretch of St. Clair West that ducks beneath the Georgetown rail corridor, between Old Weston Road and Keele Street, is as close to a traffic funnel as can be found anywhere in Toronto.

Densely populated neighbourhoods fan out to the east. To the west sit acres of car-friendly big box stores, with more on the way. Since construction this year closed a shortcut around the area, cars, buses and trucks crawl through the underpass, which offers one lane in either direction. Streetcars use a dedicated right-of-way.

You stand here for a little while and youll get a glimpse of what the people deal with everyday, Don Panos, chair of the St. Clair Gardens BIA, said recently as he stood at the corner of Old Weston, watching trucks trying to make tight right turns as cars backed up towards Caledonia. You just see how frustrating it is.

Council is considering how best to break the logjam, recently voting for an environmental assessment. One idea, favoured by the areas representative, Cesar Palacio, is to add two lanes to the underpass, but its a highly complex venture that would take years to complete and would cost more than $30-million.

Traffic engineers say the problem isnt just the width of the underpass; it also involves the constricted layout of busy intersections at either end, which regulate the volume of traffic passing beneath the 80-year-old bridge.

During the construction of the right-of-way, the intersections were not built according to approved designs because the city wanted to cut the cost of the land acquisitions needed to widen parts of the roadway, TTC experts said.

We have intersections that are not designed in accordance to what was agreed to, said TTC service planning manager Mitch Stambler. Decisions were made that were outside the planning and EA process by the construction managers.

Gord MacMillan, the citys director of design and construction, acknowledged that pressure to complete the project made it impossible to buy the additional strips of land for new turn lanes. As well, city project managers encountered technical problems that didnt surface during the planning process, he said.

Its impossible to know if the original design would have eased congestion. Yet the question is not moot. Traffic will swell in coming years with waves of new development. Metrolinxs Air Rail Link, slated to run on the Georgetown corridor starting in 2015, will make it much more complicated to rebuild the underpass once it is operating.

How to open the bottleneck:

The rest is here:
Anatomy of a bottleneck