The Basketweave

A simplified diagram of the Basketweave interchange

Looking west toward the Basketweave

The Basketweave is the name of a stretch of Highway 401 in Ontario, Canada, immediately east of the Jane Street underpass in Toronto; the name derives from the interesting criss-crossing design of the roads, which evokes imagery of a straw basketweave.

For the westbound Highway 401 driver, the functional aspect of the Basketweave is to allow drivers in the express lanes to change into the collector lanes, from which they can subsequently enter Highway 400. The Basketweave also enables the reverse lane change (from collector to express), acting similar to an express-collector exchange site. Users of eastbound Highway 401 also enjoy the facility of changing from express to collector, and vice versa, because of the symmetric design of the Basketweave.

The Basketweave was completed in 1967 as part of a major project to widen Highway 401 to a collector-express system. Despite the speed limit on Ontario freeways being raised in 1968 from 50 mph (80 km/h) to 70 mph (112 km/h) (later reduced to 60 mph (96 km/h) in 1974, then 100 km/h (62 mph) with metric conversion in 1977), motorists must reduce speed to 70 km/h to navigate the underpass safely (the overlaid transfer flyover is restricted to 80 km/h); all of the other 401 collector-express transfers (and vice-versa) allow the 100 km/h standard speed. The flyover ramps were rehabilitated in 2001.

Toronto-area radio broadcasts often refer to The Basketweave to describe traffic flow along Highway 401, for example: "Eastbound traffic is moving slowly east of the Basketweave."

The basketweave viewed from a flyover ramp heading towards Highway 401 from Highway 400.

Other basketweaves

Highway 401 near Highway 409

The main collector-express setup of Highway 401 westbound has a basketweave between Islington Avenue and Weston Road at 43°42′41″N 79°32′50″W. Here, the collectors eventually split off and default on Highway 409, but the basketweave transfer allows collector traffic to move back onto Highway 401, whose collector-express setup ends at this point. Express traffic also has the option of using the overlaid flyover transfer to reach Highway 409.

Highway 401 near Hurontario Street (2012)

Another collector-express setup of Highway 401 in Mississauga will have a basketweave between Highway 410 and Mavis Road according to the Ministry of Transportation proposal.

The Transfer

Highway 401 eastbound has another collector-express exchange near Toronto Pearson Airport at 43°39′30″N 79°36′56″W, known as the "Transfer" on the MTO Compass traffic cameras. Unlike the other examples, the Transfer does not use a flyover structure to separate the criss-crossing transfer lanes; rather, the express to collector ramp passes under a rigid concrete frame structure cut into an embankment.

This was completed in 1986 when collector lanes were added to Highway 401 between Highway 403/410 and Highway 427, providing a direct link between these freeways. Since the collector lanes beyond the transfer merely serve as ramp extensions to Renforth Drive and Highway 427, motorists wishing to continue eastbound on Highway 401 must leave the collectors at this transfer. Highway 401 express east of this transfer is congested due to only four lanes (widened from three) passing through the 427 interchange; the collector-to-express transfer often serves to make this worse.

Highway 427

Highway 427 also has basketweave transfers in both directions between the Bloor Street overpass and Dundas Street interchange at 43°38′00″N 79°33′31″W. This was completed in 1972 when then-Highway 27 was expanded to its current configuration and renamed 427.

A major complaint of this exchange is that the collectors south of Dundas are underused due to their complete lack of direct access to the QEW/Gardiner. It is for this reason that the southbound collector to express transfer is busy during rush hour, causing a major bottleneck as it merges with the express lanes, while the overlaid express to collector ramp does not divert enough traffic to compensate. In 2001-2002, improvements were made to the QEW-427 interchange to allow the southbound collectors to access QEW eastbound (Gardiner Expressway) via a new loop ramp, which was supposed to take some pressure off the collector-to-express transfer. However, there is still no southbound collectors to QEW westbound access.

The flyover ramps were rehabilitated in 2002.

See also

• Highway 401