Road Types (USA) – comprehensive overhaul of drivable roads

Map Editors Community United States US Wiki Discussion
1

Quick link: Proposed revision to Road Types (USA) drivable types (Freeway, Highways, Streets)

Road types aren’t just for show, they make a difference in the routing server. The server doesn’t have the time or resources to look at every single street between where you are and your destination, so it uses road types for guidance in selecting the best route for you. Road types aren’t everything — of course, Waze uses actual and historical traffic speed data to select the fastest route for you at a given time — but they are important. They show Waze which roads to check when looking at that traffic speed data. So setting the type too low can mean Waze doesn’t consider a road which may actually get you there faster.

Freeways are a fact of life. While freeways are by design often the fastest way from A to B, we all know this isn’t the case every time. Sometimes a freeway just isn’t convenient. Other times, freeways are clogged with traffic, while surface streets flow rather freely. Sometimes both situations are faced — without traffic, maybe the freeway adds 5 miles to your route, but it’s faster anyway; today, though, the freeway is backed up and taking the 5-mile-shorter route will save you time.

Freeways are the highest type of road in Waze, often assumed by the routing server to be the best alternative. Sure, they often are, but that isn’t always the case. For Waze to consider other roads as viable alternatives, there need to be other relatively high type roads — Major and Minor Highways — in the area for Waze to consider, or else you might just end up on the freeway in that traffic jam anyway.

Further, road types are increasingly important for longer routes. Yes, Waze is designed as a commuter application, but it’ll provide routes up to a thousand miles. I’ve used Waze on dozens of thousand-mile-plus road trips, and it’s performed admirably. And some people just have long commutes. Well, as we know, many lower-type roads are not considered at all by the routing server for routes longer than a certain length. The longer the route, the higher the road type has to be. For travel within a state, Minor Highways could be enough. For travel through the States, you want at least a Major Highway.

The current rules for setting road types in the United States are based on the physical characteristics of the road and are somewhat nebulous. The vagueness of the standards leads to inconsistent application, with editors in different parts of the country using different criteria for choosing road types. This leads to an inconsistent user experience across the country, even within states. It’s even led to disputes, with editors who disagree on what type best suits a particular road, switching the type of a road back and forth.

Luckily, the federal government has a solution for us. The Federal Highway Administration (FHWA) has come up with a set of standards by which every road in the country is judged: functional classification (very short explanation here). The functional classification of a road is determined both by the physical characteristics of a road and by the Average Annual Daily Traffic (AADT) — the number of cars that, on average, drive on a particular road each day. Each road is therefore placed in one of the functional classes; each functional class describes a particular usage scenario for the roads in it. The functional classification criteria are passed on to the several States, and each state’s department of transportation in turn uses the criteria and their own research to gather information, to classify roads, and to publish maps showing the functional class of every road in the state.

The federal government further provides guidance to us by designating roads as parts of the Interstate Highway System and the United States Numbered Highways system. The roads themselves are built and maintained by the states; but in selecting the routes, the federal government identifies a network of important long-distance travel routes throughout the country. Finally, the government of each State (and D.C., and some territories) designates roads as parts of its respective state highway system; these routes are selected for their importance in travel within a particular state.

Luckily for us, functional classification and the various highway systems comport quite well with Waze’s set of road types.

[table][tr][td]Functional class / highway system[/td][td]Waze road type[/td][/tr][tr][td]FC: Interstates
FC: Other Freeways and Expressways (some)
HS: Interstate[/td][td]Freeway[/td][/tr][tr][td]FC: Other Freeways and Expressways (others)
FC: Other Principal Arterials
HS: U.S. Highways[/td][td]Major Highway[/td][/tr][tr][td]FC: Other Arterials
HS: State Highways[/td][td]Minor Highway[/td][/tr][tr][td]FC: Major Collectors
FC: Minor Collectors
HS: County Routes[/td][td]Primary Street[/td][/tr][tr][td]FC: Local[/td][td]Street[/td][/tr][/table]
This system has already been put into place for testing in various metropolitan areas, including New Orleans and Detroit. Besides the clear improvement in definitiveness of road type selection, many other editors and I have noticed a marked difference in the performance of the routing server and in other aspects of Waze since implementing the systems.

Advantages

  • Waze is more likely to select the best possible route at the start, without you having to ask for alternatives
  • Waze is more likely to select alternative routes in the case of clogged freeways
  • The map display becomes more useful, showing the most important roads with thicker lines and at higher zoom levels — and, bonus, allowing you to see at a glance where the “downtown” area of a city is (examples: New Orleans; Detroit)
  • As said above, as a well-defined system, it does not allow for disputes and may make frivolous edits easier to discover
    Disadvantages
  • Temporary: Currently, road type is the primary factor used to judge traffic jam highlighting. That said, I’ve been using Waze daily in New Orleans for months with this system in place and have not seen any instances of erroneous jam highlighting. Also, staff has announced that road type is soon to be replaced as the principal jam-highlight criterion with something else based on the actual jam-free speed of the road.
    Many discussions have been had about the merits of such a system, and most editors have come out in favor of such a system. Experience will show that this system works, and it works well. It takes a lot of the guesswork out of editing, and it has the potential to improve routing considerably. In fact, many editors are using this system already in their states and areas.

Here is the proposed page: https://wiki.waze.com/wiki/Road_types/USA/Revision

Note: As you’ll see, this doesn’t cover non-drivable and non-public road types (parking lot roads, private roads, walking trails, etc.). While much of that section of the article does need revision, it should be carried out in another thread.

2

Proposal on the page naming:

Since this is a US centric page, when we go live with it we should make it [[Road types/USA]]. This will allow a page above it called [[Road types]] that directs to each country. I proposed this in a different thread and I have been working on moving pages that are country specific to subpages to prevent inter-country user confusion.

On your point of this only being drivable roads, this is perfect because the current page is way over the limit of good Wiki practice for content size. We may want to consider

  • [[Road types/USA]]: Brief overview of road type selection with (at least) two sections linking to the following subpages.
  • [[Road types/USA/Drivable roads]]: Your new proposed content.
  • [[Road types/USA/Non-drivable roads]]: The other content you did not yet update.

I am open to debate on the Drivable vs Non-drivable naming if there is something more applicable here that I might not be thinking about.

I will further review the rest of the content over the next day or so. I see the page came from an older version you had been working on. Did you already update your page with all the current content of the latest version of the current page? I am not saying I see any difference, just thought I would confirm.

(Note: I added the construction template linking to this forum in case someone ran across it and wanted to make changes. Feel free to modify the template parameters as you desire.)

3

Isn’t your current mapping a modification on that table where US/SR are always Major/Minor unless FC says it should be higher?

4

Thank you, Sketch, for the effort invested in this. At present, I am an FC holdout for three reasons:

  1. Ehud said, “Please, don’t do that,” after Andy’s FC briefing at the last NA Meetup.
  2. I look at the areas where FC is in use, and do not see any reduction in “Wrong driving direction” URs compared to where FC is not in use.
  3. It is a workaround to get Waze to do what it should do inherently. Road type should not be a routing factor per this post https://www.waze.com/forum/viewtopic.php?f=212&t=48543. Is not a claim of FC that road type does impact routing?

Never-the-less, FC mostly aligns with what I requested AL, FL, and GA editors do, which is:

Interstate/Freeway = Freeway
US-xx = Major Highway
SR-xx = Minor Highway
CR-xx = Primary Street

This does not impact routing any more – or less – than FC as far as I can tell, but has the advantage of being concise. For my experience, I wish Waze would just adopt Google’s routing engine and be done with it, but that’s beyond the scope of this discussion.

Best to you,
banished

5

Yes, we’re still waiting (since last meetup) for feedback from Ehud.

My main problem with typing by naming (i.e. US-## must be typed X) is that those roads (both US-## & SR-##) can vary from one lane in each direction with stop signs to 2-3 lanes each direction with traffic lights to full blown limited access highways… Each of those are drastically different types of road.

6

Thanks for the efforts, sketch. I have to say the FC idea is growing on me, at least in the less urban parts of New Jersey. But in the more urban parts of especially northern New Jersey, the FC maps do not really coincide with the objectives Waze claims for the road types to meet.

From what I understand, the higher road types in Waze are meant to narrow the network of possible routes to consider for really long trips - I would imagine we’re talking 50+ miles in the scope of MH and Fwy, if I’m not mistaken. Many of the urban routes that New Jersey calls principal arterials are not meant to be principal arterials across the entire state or even across the multiple counties, like Waze is looking for with the higher road types, but rather just the principal arterial through that specific urban area. Many of these roads are simply surface city streets with traffic lights, no concretely defined turn lanes/signals, parked cars, and even very frequent residential/commercial driveways, and are simply not appropriate for even being considered for routing in the middle of a 50+ mile trip. Fact of the matter is that in such highly-urbanized areas, controlled-access freeways are really the only roads appropriate for through travel. If there’s an accident, you can try another freeway - there’s usually many of them in very urbanized areas. If you’re past the point of detour to another freeway, unless the freeway is actually closed, the ugly reality of these heavily urbanized areas is that your fastest option is probably to just wait out the congestion on the that freeway.

Ironically, Bing seems to have the best metaphor for road types that I’ve seen so far. I’m not saying that we should rush and adopt their standard; I don’t even know exactly what it is or whether it would suit Waze’s objectives, but if you look at New York City on Bing Maps, there isn’t a single major non-freeway highway anywhere inside the outermost I-287 loop, except for a few short connector sections of roads where a controlled access freeway was never built. Even multi-lane divided roads in this area are mere minor highways, because they’ve been replaced with nearby controlled-access freeways far more appropriate for longer-distance travel.

I’m not trying to single out New Jersey, but it’s where I’ve done and continue to do the vast majority of my editing. Though I know our roads are rather quirky, I’m pretty sure there are other states, at least here on the east coast, that have similar issues with a strict FC interpretation.

Maybe I have the objective of the road types totally wrong, but if they are for trying to single out roads appropriate for use in the middle of trips of certain distances, then urban arterials are a bad metaphor for Waze highways.

7

Thanks for the input, all, I appreciate it.

With the next NA meetup looming as close as it is, of course I’m perfectly comfortable waiting until then before implementing it nationally.

Kent, I did take account of the recent-ish changes to the Overview section of the current page. I included some of that a few days ago. The rest is pretty much a wholesale change.

Regarding the US/State/County Highway correlation, I agree that that should be part of it, and it is. But that doesn’t cover anywhere near everything; there are 55 mph suburban expressways which don’t fit into any of those systems. I’m sure this isn’t what we’d intend, but I’ve seen this pushed to its extreme in the Detroit area — where US Routes were Major Highway, state highways were Minor Highway, and every other county- or municipality-maintained surface-street thoroughfare was Primary Street, including that 55 mph expressway I mentioned. Routing left quite a lot to be desired. Like I said, I know that’s not what we’d intend by that standard, but the point of including functional classification is to have definite answers for those roads as well.

That’s one function of higher road types, the other seems to be during the initial route pruning process. Cities have Freeways too — the highest type road — so if you give the server a couple Major Highway alternatives to choose from, it’ll be more likely to “see” an alternative route in case of traffic on the freeway. Upgrading to functional classification — which, yes, means Major Highway on 35 mph roads with lights — added a third route to my daily commute besides the 2 freeway options. It only routes me along that route occasionally, when traffic is especially bad on the other two, but for those occasions it’s worth it.

In Detroit I saw a much bigger difference (because Detroit’s much bigger and has way more roads to choose from); basically where it used to make me backtrack to get on the nearest freeway entrance, it now sends me along a Principal Arterial (Major Highway) or two for a few miles to get to the next useful freeway entrance downstream. It actually saves a couple minutes.

8

I would like to see the rationale documented for the exception for ramps to be used for at-grade connectors.

9

I favor the use of functional classification. But I see a possible deficiency.

I believe that primary street should be used for the main road linking two rural towns (and presumably thus the main street through the town) when no higher classification applies (which is often the case). This could well require local knowledge of the editor rather than a published document. Functionally the street is the primary route even though there isn’t much traffic.

10

The exception for at grade connectors is in the Wiki here http://wiki.waze.com/wiki/At-Grade_Connectors#Exceptions. Are you asking something different?

Ah maybe you are suggesting we explain “why” we need the ramp in order to get the “Exit right” instruction. That looks easy enough to add. Then we can link it to the ramp entry.

11

– Except that when this was posted, in that article there was not even mention of the new situations (in which to use a ramp for an AGC) listed in sketch’s draft article (the subject of this thread).

Which is correct. Those were the only situations mentioned in sketch’s draft. But there was no link at the time I asked from sketch’s draft page to any rationale in the wiki or even in a forum thread.

Later:

This sounds like a suggestion that someone should document the rationale for the new situations in which an exception applies for a ramp as an AGC.

<Edited to explain time warp.>

12

I am afraid your responses are too cryptic to understand. Please use more words.
I have made changes to https://wiki.waze.com/wiki/At-Grade_Connectors#Connector_is_a_signed.2C_numbered_exit that I believe are helpful in describing why these at grade connectors should be ramps.

If you are looking for something different please spell it out.

13

Comment: in general, I think FC is a good basis for assigning road type; I think the references to route numbering should be removed. In practice, there is a fairly high degree of correlation between route numbering and road function, but it is definitely not 100%. In those cases where a US highway serves the function of a minor highway because it travels along a narrow street with traffic lights and driveways, or where a state highway serves the function of a major highway because it has few intersections and permits high-speed through travel, the road’s function should take precedence over its numbering.

The references to “county routes” are useless in Virginia, since we don’t have them, and in most counties literally every street, from the eight-lane arterials down to the 200-foot dead end around the corner from my house, has a “secondary state highway” number that is absolutely meaningless in terms of Waze’s mapping needs.

14

Same goes for Connecticut - no County Roads. There is also an entire series of unsigned state route numbers in CT as well - basically everything from CT-400 & up… I’ve been slowly removing references to those (almost all alt-names) as I’ve come across them. For more info on the unsigned road network in CT, see http://en.wikipedia.org/wiki/List_of_State_Routes_in_Connecticut

15

I think that it is key to reinforce that having a glut of principal arterials classed as MH still helps direct or funnel longer distance routes to a freeway. Even when presented with numerous principal arterials, as long as the freeway truly is the fastest route, Waze will opt for freeway even if it is way out of the way (assuming “fastest route” intended). To one of PhantomSoul’s points, I agree that most urban principal arterials are meant for more local use (i.e. non-freeway suburb to suburb or even intra-city) and and not long distance trips, but those are also mixed with US and some major state routes that also have the principal arterial designation and would be more suitable long distance routes. In any case, you still normally get “sucked” onto a freeway as long as your “avoid major highways” option is disabled, but you also have legitimate alternatives at a lower road type if appropriate from the start–not just mid-route as a detour or in the first or last few kilometers.

As an example, entering downtown Detroit from the east side of Ann Arbor/Ypsilanti (about 40 miles), there were only two initial routes suggested pre-NFC: 1) I-94 all the way, and 2) backtracking to get to US-23 to M-14 to I-96 (all freeways). Looking at my routes now from the same location, my primary route is still I-94 (purple in the image), but look at the two alternatives. The green is a bypass off of I-94 using state highway M-39 (previously mH in that stretch, now MH/principal arterial) for about three miles to join I-75. This was not even an option before but it is only three minutes more than the direct I-94 route. The blue alternative is part of the pre-NFC suggested route, but instead of backtracking to take US-23 to M-14 to I-96, Waze now suggests a road straight north to get to M-14 (previously primary street, now mH/minor arterial).

Another consideration is that people should look at how their state DOT actually classifies the roads in your state if you have not. You will find that some states fit the traditional Waze road types well, and others are nowhere close. sketch references the links on each state’s mapping resources page, but since those are not altogether complete, here is a link to current FC maps.

Agreed, but this is an area where different DOTs may treat things differently, so it’s worth looking at this in more detail. Some may lower the functional classification of a road such as US-XX through a lower-speed, full-access urban stretch while others (including Michigan) typically do not. We have some state highways at mH and plain city-controlled roads as MH in numerous cases when applying FC. Politics, funding, etc. may come into play with a designation too as sketch mentioned.

I believe that dbraughlr may be referencing the bit about jughandles and Michigan lefts specifically. In the case of Michigan Lefts, sketch tested and tweaked the exception for a signed but unnumbered at-grade exit from a roadway. It has to meet specific signage criteria and be at an actual major intersection, not just a standard median crossover. By the way, as GizmoGuy411 and I built that section of the Michigan wiki explaining Michigan Lefts (a colloquial term), we settled on the term “Median U-Turn Intersection” as the best documented naming convention, especially as these are employed under numerous names throughout the US, and they are increasing. If the exception part stays on the revised Road Types page, I believe it should go toward the more or less “official” name for these styles of intersections. Drop “Michigan Left” in favor of MUTI… It should be an at-grade exception in more than a few people’s opinions. I think this is mostly because an instruction like “to Telegraph Rd S / US-24 S / to Grand River Ave W / M-16 W” is a bit much to see on a 10-15m segment and pollutes the visual. “Ramps” don’t have street names–they carry instructions. The same goes for jughandles and MUTIs.

Perhaps this page does not go into enough detail about how to apply FC in certain circumstances, or perhaps that should be somewhere else, but the guideline as adopted in Michigan when we went FC statewide was to never downgrade a road type just to match functional classification, but it would be okay to maintain or upgrade based on local editor knowledge. Also, we had another one such as what to do with dirt roads, particularly since a number of minor collectors in our state are dirt.

16

Regarding state highways: I’m aware that many states have sort of ridiculous state highway systems. That’s the purpose of the “Note” at the end of the Minor Highway section. Louisiana’s highway system is ridiculous. At least you guys have the >400-series / secondary routes distinctions there; ours are assigned sequentially so the number is, functionally, almost useless. At least most of the 0.05 mile state highways were finally removed in 2010. Anyway, I will include in the note a link to the state mapping resources pages, and each state mapping resources page should if necessary include a rule about secondary state highways.

Regarding County Routes, the Primary Street section does say that “Some states designate county routes” (emphasis added). The rule is there for the states that do.

Regarding adding numbered routes in general, I find it adds quite a lot to rural areas where functional class is of limited help. Of course it depends on the state, but for sake of example, look at the LA functional class state map (large file ~10MB); some areas around Bienville, Jackson, Ouachita, and Winn Parishes, and the Gulf Coast in Cameron Parish in the southwest corner; are 30-40 miles from the nearest Arterial. Instead of one taking precedence over the other, whichever is higher takes precedence instead — Waze can use traffic data to discount a higher-type road, but not to count a pruned lower-type road.

17

Sketch, in this section it appears it would be good to add more in explaining why the Jug handles and MI left, in addition to the turn lanes, should use the ramp type. Perhaps we can link to the more detailed article that I have already updated here and include the Jug Handles and MI left to this page as part of the explanation.

18

Very good post, davielde, thank you.

Kent, I will do that. Is there a thread concerning that at-grade connectors page? Seems like we should add jughandles, unnumbered exits which are signed for more than just the name of the immediate street to which the exit goes, and Michigan lefts to it. I think it’s only been discussed on the Michigan forum, but I think the MUTI page is ready for inclusion into the Wiki — along with a redirect from “Michigan left”.

19

If there’s one thing I’ve learned from dealing with 20 years of process and classification documentation, its that you sketch out (no pun intended) the basic idea, then build the exception system before continuing. Because There Will Be Exceptions, and you need a system in place for allowing them… probably a combination of process (approval by a regional manager or champ, for example), and a list of common exceptions that may not need approvals. For approval, there should be some minimum of guidance, or you’ll have the senior editors either tied up in knots and arguments, burnout and reactinary responses, or all of the above.

20

I believe a generalized exception for cases where an RC or champ determines a type upgrade is necessary for proper routing is sufficient, but I’m willing to get into it with making the list more specific. I do agree that a specific process is warranted.

I don’t think I can think of any situation where a user might upgrade a road type without approval. I imagine any user experienced enough with road types to make the determination that a higher type is “necessary for proper routing” will be familiar enough with their area’s champs/RC anyway that contacting them will be a non-issue; and further, the champ or RC may grant more latitude to certain experienced editors in making this judgment within a particular area or region.

I don’t envision that champs/RCs will have too hard a time understanding why other champs/RCs have made these determinations. Perhaps oversight via posting all such determinations to a state’s Wiki or forum will be sufficient.