Traffic Management during the Construction of Canada Line

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Traffic Management during the Construction of
Canada Line Application of Variable Demand
Assignment Procedure Presented by Edwin Hull,
Edwin Hull Associated Ltd. Billy Kwok, SNC Lavalin
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EMME/2 Modelling

• Forecast volumes on affected roadways during
  construction Estimate delays and increased
  travel times Forecast volumes diverted to
  alternative arterials Assess impacts of traffic
  diverted to local streets Assess impacts on
  transit operations
• Develop measures of mitigation

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Modelling Outputs Required
  Reliable detailed intersection turning traffic
forecasts  Reliable estimates of
delays  Reliable forecast of traffic increase
on parallel arterials  Reliable forecasts of
traffic on neighbourhood roads
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Outputs Not Required
 Long term demand forecasts Alternative
demographic inputs Transit Ridership Forecast
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Model Development
 Strategic Greater Vancouver Model
Unsuitable City of Vancouver Sub-regional
Unsuitable Need for Detailed Sub-area
Assignment models     Downtown
Vancouver     Cambie Street Corridor
    No. 3 Road Corridor
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Model Structure
Weekday AM and PM Peak Hour Auto
Assignment-Only Explicit Representation of
Intersection Laning And Signal Operations
Validated To Regional Screenline Counts Subarea
Intersection Counts Detailed Mesoscopic Inset
Within the Macroscopic Regional Model.
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Synthesis of Signal Operations

• Turn Capacities Based on
• No of lanes
• Saturation Flow per lane
• Green time
• Cycle length
• Total traffic in shared lanes
• Opposing traffic volume (for permitted left
  turns)
• Pedestrian interference (right turns and some
  left turns)

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Synthesis of Signal Operations

• Capacity Green time / Cycle length Saturation
  Flow Ped Factor
• Saturation Flow
• 1800 veh/hour per lane for thru traffic movements
• 1600 veh/hour for turn lanes
• Ped Factor based on available pedestrian counts

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Synthesis of Signal Operations

• Turn Delays Based on
• Cycle Length
• Green Time
• Volume/Capacity

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Turn Delays

• Dedicated Lanes Protected Phases
• Base Delay ((Cycle length green time) 2) /
  2 Cycle length
• Congestion Delay (volume/capacity) 4
• fp50 (ep1 - ep2) 2 / (120 ep1) ((pvolau
  pvolad) / ep3) 4
• Where
• ep1 cycle length (seconds)
• ep2 green time (seconds)
• ep3 capacity (vehicles per hour)

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Shared Lanes

• Shared thru and right with no separate dedicated
  thru lane
• Shared thru and left with no separate dedicated
  thru lane
• Shared thru and right with a parallel dedicated
  thru lane
• Shared thru and left with a parallel dedicated
  thru lane
• Shared thru/right separate shared thru/left, no
  other thru lane
• Single approach lane for the thru movement and
  both turns.

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Shared thru/turn, no separate thru lane

• Initial capacity based on dedicated lane for each
  movement
• Capacity factored by share of previous assignment
  volume

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Shared thru/turn, separate thru lane

• Capacity for turn based on dedicated lane
• Thru capacity in shared lane factored by unused
  turn capacity
• Shared lane capacity added to thru capacity of
  dedicated lanes

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Two Shared Lanes, No Separate Thru Lane

• Capacity for turns based on dedicated lane
• Thru capacity in shared lane factored by unused
  turn capacity
• Thru capacity set at sum of net shared lane
  capacity
• If thru volume capacity, shared capacity
  approach applied

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Single Lane Approach

• Typically low volume intersections
• Local road intersects with major road
• Width of allows thru traffic to bypass left
  turning vehicles
• Treat as separate left turn lane and shared
  thru/right lane.

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Permitted Turns

• Two sneakers per Cycle
• Gaps in opposing through traffic flow
• Cp 0.25 Vot / Cot gp / c 1600 L 2
  3600 / c
• Cp capacity of permitted left turn phase
• Vot Opposing thru traffic volume
• Cot Opposing thru traffic capacity
• gp Green time for permitted left turn
• c cycle length
• L number of permitted lanes

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Capacity Comparison
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Capacity Comparison
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Implementation

• Extra turn attributes
• _at_tncap turn capacity
• _at_lanes number of lanes and indication of lane
  sharing
• _at_green green time
• _at_cycle cycle length
• _at_sfact pedestrian factor
• _at_tfact capacity factor for shared lanes
• _at_nema approach direction code
• Temporary use of ui1, ui2, ui3, up1, up2, up3

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Implementation

• For turns, _at_lanes number of (dedicated or
  shared) lanes
• Thru, _at_lanes dedicated thru lanes 0.25 for
  shared thru/RT 0.5 for shared thru/LT
• Capacity based on truncated integer value
• _at_lanes.mod.1 (0.25, 0.5 or 0.75) identifies
  shared capacity calculation(s) required
• Pedestrian factors (_at_sfact) based on pedestrian
  counts and anecdotal evidence.

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Direction Code
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Dynamic Capacity Adjustment

• Iterative Procedure
• Gen cost Assignment (60-iterations) and capacity
  adjustment
• Six cycles of assignment and capacity adjustment
• Stable converged state

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Base Demand Matrix Adjustment

• Initial matrices disaggregated from regional
  model
• Validated against the counts with demand
  adjustment macro
• Short Trips Constrained
• Constraints applied to preclude large cell values

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Validation Results
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Demand Suppression

• Driver Response to Capacity Reduction
• No change in behaviour.
• Change route.
• Carpool
• Change mode (transit, walk or bicycle)
• Change to a less congested time period.
• Change destination. (Other than work or
  education)
• Make no trip at all.

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Variable Demand
Variable Demand Assignment of Base Matrix
  fa1 mat1 (1.33 ( (mat2 - upqau) / (mat2
1))) Where mat1 Validated Based Demand
Matrix mat2 Based Network Generalised Cost
Matrix
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Thank You!