Congestion Network 2.0: Segment and define Highway

[chmnata]

Highways irl usually do not physically intersect with other roads as they are normally overpass, with the exception of ramps. However, for centreline, roads don't really take into account of overpass and underpass, so where highway and other roads overlap in a 2D sense, there will be an intersection. For example: In centreline, there is an intersection in centreline_intersection at every overlapping roads,

Even though they don't actually intersect

In here's map, they do treat overpass and underpass as separate roads, so they don't necessary intersect all the time Completely not ending at intersections:

BUT sometimes they do:

Not sure how I should segment highways into smaller sections...I think we could segment them at the closest intersection, and skip intersection if its just completely not intersecting it.e.g. spadina and gardiner

@radumas do you have other ideas on how we should segment them?

[chmnata]

Checked data requests that asked for lakeshore or gardiner data, there were not a lot and most requests regarding those highways were asking for volumes.

Requests asking for tt: Gardiner Rehab

• Gardiner Expressway to/from Park Lawn Rd and York St
• Lake Shore Blvd to/from Park Lawn Rd and York St

Nuclear Request

• Gardiner - HW427 to/from DVP (break at px the best we can)
• Lakeshore Boulevard - Etobicoke Creek to/from DVP (break at px the best we can)
• DVP (has no px so we break at major arterial where we can)
• HWY 427 (Break at px)

Speed limit reduction

• Lake Shore Boulevard West - Humber River to a point 100 metres west of Spadina A
• Lake Shore Boulevard West (eastbound) - South of Frederick G. Gardiner Expressway, between Palace Pier Court to Humber River"

I feel like breaking at px and major arterial where we could is the way to go. If it doesn't end there then 🤷🏼

[chmnata]

Cases where I skipped the breaking (WIP): Gardiner: Gardiner WB at Spadina Ave, gonna cut it at around 360m east of the gardiner and spadina intersection Eastbound does have a node so it will be segmenting at Spadina.

Gardiner EB at York St, cutting at around 73m west of the gardiner and york st intersection Westbound does have a node

DVP: DVP NB at Pottery Rd, cutting at around 105m south of the intersection SB has a node

HWY-427: Highway 427 N at Albion Rd, cut at 200m s of the intersection SB has node

HWY-401: Highway 401 Expressways at Nelson Rd cut at 300m west of the intersection

[radumas]

Express lanes on expressways make this more complicated.

IDK I still feel like using intersections with ramps or whatever ramps between express and collector are labelled as is logical from a few perspectives: you could present the estimated travel time a display would read from an on-ramp to someone's desired exit and the link_dir will certainly break at all those locations, so maybe fewer manual interventions?

But... :meow_dunno: seems like you've expended some effort on this approach, can always revisit next year :meow_coy:

[chmnata]

Selected highways based on Expressway field in centreline. SO it does not include HWY-27 or Lake shore blvd since those are tagged as major arterial in centreline, this implies that those segments will use a baseline of 10th percentile spd instead of a 25th percentile of spd when calculating tti 🤔 .

Neon pink as highways.

[chmnata]

Discussion with @radumas: do some analysis on the highways and baseline.

[chmnata]

Deleted the highway table and added a new boolean highway field in congestion.network_segments. Doing this we will be joining one less table during aggregation and have one less table to monitor for versioning .