Talk:Chicago Area/Highway Classification

Lined with buisnesses

• I think that the contributing factor that secondary roads are lined with businesses should be removed. Lining with businesses is actually problematic to making connections between places (turning traffic and driveways end up slowing down through traffic) Nonetheless businesses line lots of busy roads simply because they can capture the demand which is already there --Popball (talk) 15:40, 7 May 2023 (UTC)
  • In the city, almost all of the roads have turning traffic that can slow the flow. This classification is determine both connectivity and use of the roads within the area. I changed the description to clarify a bit better as a secondary condition describing how roads are usually business lined and primarily controlled with traffic lights. reasoning is that the buisness lined, major roads will usually only be controlled by traffic lights as residential lined major roads will also have stop signs slowing traffic for residents. it is a complex grid system. Nickvet419 Flag of United States. 00:43, 8 May 2023 (UTC)

Functional Classification

While not always aligned to OSM's definition of highway classification, IDOT provides a tool to see the functional classification of various roads: https://www.gettingaroundillinois.com/MapViewer/?config=RFCconfig.json Note that this is made for funding purposes, but it can help us determine what IDOT considers the purpose of the road: Minor arterial suggests highway=secondary and major collector suggests highway=tertiary for example. --Popball (talk) 13:52, 22 May 2023 (UTC)

The IDOT Functional Class map is similar to what is outlined on this page with major collectors cutting though neighborhoods with signalized intersections and the seporation between urban and rural areas. I think it gets a little messy the closer to the city center it gets. Another thing is we don't want to encourage people to copy other maps. --Nickvet419 . 18:35, 22 May 2023 (UTC)

Yeah, unfortunitely Illinois law does not put state works automatically into the public domain like the federal government. Nonetheless, considering what the functional classification is (and the state as the primary source) while making our decision is completely OK. Likewise, we can consider traffic counts (also from the IDOT). However, both of these metrics are usually more useful as tiebreakers between two routings.

The messiness downtown stems from the fact (IMO) that it is one of the densest areas in the country, so you can have 4-lane street which only serve local traffic. Using physical characteristics alone will not work, thus why most of them are secondary (some incorrectly), as they look like a secondary, but most will not have significant through traffic. In fact, the network design even discourages using the grid network in the Loop as through streets, given the major streets mostly end within it (for example, how LaSalle ends at Jackson) --Popball (talk) 22:09, 22 May 2023 (UTC)

Using traffic info would not work well in this dense urban environment as even small side streets pull high amounts of traffic during rush, which lasts from 7am-7pm. Even though Lasalle ends at jackson, It would still meet the meet the standards for secondary, but you also have to remember that not the entire road does not need to be the same class all the way though. --Nickvet419 . 18:15, 23 May 2023 (UTC)