The Basketweave

The Basketweave is the name of 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. Because the speed limit on Ontario freeways was raised in 1968 from 80 km/h (50 mph) to 112 km/h (70 mph) (later reduced to 96 km/h (60 mph) in 1974, then 100 km/h (62 mph) with metric conversion in 1977), it rendered this exchange obsolete shortly after its completion. Motorists have to 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." [Citation
last = Ministry of Transportation
first = Ontario
title = Highway 401 Traffic Cameras
url = http://www.mto.gov.on.ca/english/traveller/compass/camera/loc21.htm
accessdate = 2007-07-15] [Citation
last = Canada.com
title = Traffic Watch
url = http://www.canada.com/components/camera.aspx?r=30&n=2&d=South%20side%20of%20Hwy%20401%20at%20the%20Basketweave%20near%20Jane&u=http://www.mto.gov.on.ca/english/traveller/compass/camera/pictures/loc21.jpg
accessdate = 2007-07-15]

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 [http://maps.google.com/maps?q=toronto&t=k&hl=en&ie=UTF8&ll=43.711328,-79.546675&spn=0.002718,0.005246&om=1 Google image] . 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.

The Tunnel

Highway 401 eastbound has another collector-express exchange near Toronto Pearson Airport, this is known as the Tunnel on the MTO Compass traffic cameras [http://maps.google.com/maps?q=toronto&t=k&hl=en&ie=UTF8&ll=43.65831,-79.615903&spn=0.005441,0.010493&om=1 Google image] . Unlike the other examples, the Tunnel 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, hence the name.

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 between the Bloor Street overpass and Dundas Street interchange [http://maps.google.com/maps?q=toronto&t=k&hl=en&ie=UTF8&om=1&ll=43.632659,-79.557624&spn=0.010887,0.020986 Google image] . 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, recent QEW-427 interchange improvements allowed 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.

The flyover ramps were rehabilitated in 2002.

References

External links

[http://maps.google.ca/?t=k&ll=43.674266,-79.581656&z=15 Another example] [http://maps.google.ca/?ll=43.684648,-79.607728&t=k&z=16 Another example]