Hogg's Hollow Bridge
Encyclopedia
Hogg's Hollow Bridge, originally known as the Yonge Boulevard Viaduct, is a set of four separate highway bridges that span the Don River Valley in Toronto
, Ontario
and carries 14 lanes of Highway 401. The four structures are the busiest multi-span bridge crossing in North America, surpassing the Brooklyn Bridge
.
The road surface and bridge decks require constant maintenance due to the wear and tear from high traffic volumes. Since 2001, an Ontario tall-wall concrete barrier has replaced the steel guiderail in the median separating eastbound and westbound traffic. The late 1960s conventional truss lights have been replaced by high-mast lighting. Starting from 2002, the westbound collector lanes on the outer north bridge have also undergone rehabilitation (replacing road surface, guard rail
s and/or concrete barriers). The westbound collector traffic has been rehabilitated; the project included the north side outer bridge and the Yonge Street
overpass. Additional high mast lighting was added in late 2009. From 2006 to 2008, the eastbound collector lanes were rebuilt and the reconstruction stretched from east of Avenue Road all the way to Bayview Avenue
, encompassing the south side outer bridge and Yonge Street overpass. This did not include the onramp junction with Lord Seaton Road. The inner eastbound express lanes will be next on the reconstruction process. Once completed, the entire bridge will use the Ontario tall-wall barrier system.
Due to land constraints of the Valley and the need to accommodate the bridges, the adjacent interchange with Yonge Street is of a modified Parclo design instead of the typical Parclo A4 configuration used on most Ontario freeway junctions. The interchange is also one of the narrower points of Highway 401's collector-express system, not just because of the bridges but also because of the suburbs east of Yonge Street (which forced the province to expropriate land in order to expand that segment of Highway 401). Although there is a total of 14 lanes of traffic on the four bridges, there are only 12 through lanes that cross Yonge Street, as the offramps and onramps default onto the main lanes instead of being additional de-acceleration and acceleration lanes.
At the foot of the bridges is the Earl Bales Park and Ski Centre in the north and Don Valley Golf Course
to the south, both owned by the City of Toronto.
An access road branches off from the westbound onramp and travels downward to the valley below and ends in a cul-de-sac
just south of the eastbound collector lanes. It is closed to regular vehicular traffic and used by MTO
maintenenance crews (and their contractors).
The bridges can be clearly seen from Yonge Street
looking northwest and north of York Mills Road
and Wilson Avenue.
s were constructed beginning in early 1928, and opened on January 5, 1929, providing a much needed bypass of the deep ravine. It also provided as a detour for motorist connecting from Wilson Avenue to York Mills Road as both roads did not meet at Yonge Street. The Toronto Bypass, today's Highway 401, was routed over the bridge in December 1952.
The collector (outermost) spans are girder bridge
s were opened in December 1965 during the widening of Highway 401 to a collector-express system. A conventional lighting system with truss-neck poles was added to the bridges (and the rest of the widened 401) around this time.
In 2008, Morrison Hershfield
was retained by the Ministry of Transportation of Ontario (MTO) as the lead consultant for a Total Project Management (TPM) Detailed Design assignment for the rehabilitation of Highway 401 at Hogg’s Hollow Bridge. This is deemed to be the most complex portion of the Ministry’s 401 Strategic Rehabilitation Program. Morrison Hershfield carried out the structural rehabilitation of a total of 12 structures including complete deck replacements at the Hogg’s Hollow Bridge, rehabilitation of the pavement structure including concrete base repairs, and was responsible for extensive construction staging and traffic management over multiple construction seasons including provision for winter staging and construction shutdown.
The rehabilitation of Hogg’s Hollow Bridge is estimated to be an $86-million construction project. Barricade Traffic Services Inc. were in charge of traffic control. The safety needs of the traveling public and workers within the construction zone were met, with minimal disruption to commuters and commercial carriers. Work on the Hogg’s Hollow Bridge saw most of the lane closures required done at night to minimize congestion on Canada’s busiest section of highway. The impact of delays on traffic from construction activities on this section of the highway would have been significant if it was not for the detailed construction staging plans and the planned mitigation of traffic impacts that were in place prior to the beginning of the bridge rehabilitation.
The expected completion date of the rehabilitation of Hogg’s Hollow Bridge is tentatively scheduled for 2012.
Toronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...
, Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
and carries 14 lanes of Highway 401. The four structures are the busiest multi-span bridge crossing in North America, surpassing the Brooklyn Bridge
Brooklyn Bridge
The Brooklyn Bridge is one of the oldest suspension bridges in the United States. Completed in 1883, it connects the New York City boroughs of Manhattan and Brooklyn by spanning the East River...
.
Description
The Hogg's Hollow Bridge has a 14-lane cross section: 6 collector lanes, 8 express lanes.The road surface and bridge decks require constant maintenance due to the wear and tear from high traffic volumes. Since 2001, an Ontario tall-wall concrete barrier has replaced the steel guiderail in the median separating eastbound and westbound traffic. The late 1960s conventional truss lights have been replaced by high-mast lighting. Starting from 2002, the westbound collector lanes on the outer north bridge have also undergone rehabilitation (replacing road surface, guard rail
Guard rail
Guard rail or guardrail, sometimes referred to as guide rail or railing, is a system designed to keep people or vehicles from straying into dangerous or off-limits areas...
s and/or concrete barriers). The westbound collector traffic has been rehabilitated; the project included the north side outer bridge and the Yonge Street
Yonge Street
Yonge Street is a major arterial route connecting the shores of Lake Ontario in Toronto to Lake Simcoe, a gateway to the Upper Great Lakes. It was formerly listed in the Guinness Book of Records as the longest street in the world at , and the construction of Yonge Street is designated an "Event of...
overpass. Additional high mast lighting was added in late 2009. From 2006 to 2008, the eastbound collector lanes were rebuilt and the reconstruction stretched from east of Avenue Road all the way to Bayview Avenue
Bayview Avenue
Bayview Avenue is a major north-south route in the Greater Toronto Area of Ontario. North of Toronto, in York Region, Bayview is also designated as York Regional Road 34.-History:...
, encompassing the south side outer bridge and Yonge Street overpass. This did not include the onramp junction with Lord Seaton Road. The inner eastbound express lanes will be next on the reconstruction process. Once completed, the entire bridge will use the Ontario tall-wall barrier system.
Due to land constraints of the Valley and the need to accommodate the bridges, the adjacent interchange with Yonge Street is of a modified Parclo design instead of the typical Parclo A4 configuration used on most Ontario freeway junctions. The interchange is also one of the narrower points of Highway 401's collector-express system, not just because of the bridges but also because of the suburbs east of Yonge Street (which forced the province to expropriate land in order to expand that segment of Highway 401). Although there is a total of 14 lanes of traffic on the four bridges, there are only 12 through lanes that cross Yonge Street, as the offramps and onramps default onto the main lanes instead of being additional de-acceleration and acceleration lanes.
At the foot of the bridges is the Earl Bales Park and Ski Centre in the north and Don Valley Golf Course
Golf course
A golf course comprises a series of holes, each consisting of a teeing ground, fairway, rough and other hazards, and a green with a flagstick and cup, all designed for the game of golf. A standard round of golf consists of playing 18 holes, thus most golf courses have this number of holes...
to the south, both owned by the City of Toronto.
An access road branches off from the westbound onramp and travels downward to the valley below and ends in a cul-de-sac
Cul-de-sac
A cul-de-sac is a word of French origin referring to a dead end, close, no through road or court meaning dead-end street with only one inlet/outlet...
just south of the eastbound collector lanes. It is closed to regular vehicular traffic and used by MTO
Ministry of Transportation (Ontario)
The Ministry of Transportation of Ontario is the provincial ministry of the government of Ontario which is responsible for transport infrastructure and related law in Ontario. The ministry traces its roots back over a century to the 1890s, when the province began training Provincial Road Building...
maintenenance crews (and their contractors).
The bridges can be clearly seen from Yonge Street
Yonge Street
Yonge Street is a major arterial route connecting the shores of Lake Ontario in Toronto to Lake Simcoe, a gateway to the Upper Great Lakes. It was formerly listed in the Guinness Book of Records as the longest street in the world at , and the construction of Yonge Street is designated an "Event of...
looking northwest and north of York Mills Road
York Mills Road
York Mills Road is an east-west route in Toronto, Ontario, Canada named for the community of York Mills or Hoggs Hollow. "York" refers to York Township and "Mills" refers to the gristmill and sawmills in the Don River valley during 1804–1926. It is the former 10th concession road.York Mills runs...
and Wilson Avenue.
History
The inner under deck truss bridgeTruss bridge
A truss bridge is a bridge composed of connected elements which may be stressed from tension, compression, or sometimes both in response to dynamic loads. Truss bridges are one of the oldest types of modern bridges...
s were constructed beginning in early 1928, and opened on January 5, 1929, providing a much needed bypass of the deep ravine. It also provided as a detour for motorist connecting from Wilson Avenue to York Mills Road as both roads did not meet at Yonge Street. The Toronto Bypass, today's Highway 401, was routed over the bridge in December 1952.
The collector (outermost) spans are girder bridge
Girder bridge
A girder bridge, in general, is a bridge built of girders placed on bridge abutments and foundation piers. In turn, a bridge deck is built on top of the girders in order to carry traffic. There are several different subtypes of girder bridges:...
s were opened in December 1965 during the widening of Highway 401 to a collector-express system. A conventional lighting system with truss-neck poles was added to the bridges (and the rest of the widened 401) around this time.
Bridge Rehabilitation
Hogg’s Hollow Bridge is situated on what is considered to be the most sensitive segment of Highway 401, averaging around 400,000 vehicles a day on weekdays. Given the importance of this segment of Highway 401 through the GTA, the Ministry of Transportation was particularly concerned with the development of construction staging plans and the mitigation of traffic during the rehabilitation of the Hogg’s Hollow Bridge. “The impact of delays on passenger and commercial traffic resulting from construction activities on this section of highway were an important consideration,” says Ron Klatt, Department Manager, Contract Administration Group with Morrison Hershfield Ltd., the engineering and management company that designed the project.In 2008, Morrison Hershfield
Morrison Hershfield
Morrison Hershfield is an employee-owned professional services firm providing engineering and management consulting services in the areas of energy and...
was retained by the Ministry of Transportation of Ontario (MTO) as the lead consultant for a Total Project Management (TPM) Detailed Design assignment for the rehabilitation of Highway 401 at Hogg’s Hollow Bridge. This is deemed to be the most complex portion of the Ministry’s 401 Strategic Rehabilitation Program. Morrison Hershfield carried out the structural rehabilitation of a total of 12 structures including complete deck replacements at the Hogg’s Hollow Bridge, rehabilitation of the pavement structure including concrete base repairs, and was responsible for extensive construction staging and traffic management over multiple construction seasons including provision for winter staging and construction shutdown.
The rehabilitation of Hogg’s Hollow Bridge is estimated to be an $86-million construction project. Barricade Traffic Services Inc. were in charge of traffic control. The safety needs of the traveling public and workers within the construction zone were met, with minimal disruption to commuters and commercial carriers. Work on the Hogg’s Hollow Bridge saw most of the lane closures required done at night to minimize congestion on Canada’s busiest section of highway. The impact of delays on traffic from construction activities on this section of the highway would have been significant if it was not for the detailed construction staging plans and the planned mitigation of traffic impacts that were in place prior to the beginning of the bridge rehabilitation.
The expected completion date of the rehabilitation of Hogg’s Hollow Bridge is tentatively scheduled for 2012.