Proposal: Upgrade our ML Divided highways to expressway

[Gazoo4U]

Reading over the Waze wiki, it doesn't seem to offer any guidelines on Expressways besides the obvious that its between a Freeway and a Major Highway.

Most road-fans consider a freeway to be is an controlled access divided highway with no at-grade intersection while an a expressway is on controlled access with a limited number of at-grade intersections. (As an aside freeways happen to be coded in Michigan State law while expressways isn't mentioned)

The M-5 Haggerty Connector and the M-53 Romeo bypass are some of the examples of expressways in our state.

However, our numerous wide divided highways such as such Woodward and Eight Mile with their implementation Michigan Lefts actually serve the same purpose. Because of two-phase light timing that the ML allows, through-traffic speed is excellent on roads and they are safer than two ways. These are obviously the preferred travel routes. Unsurprisingly they have been given Major Highway.

However, looking over the Wiki SE Michigan map we have numerous other roads also marked Major highway which are inferior to the big roads. Examples include Twelve Mile, Maple Road, Greenfield, Warren, Evergreen and Long Lake (the latter two, I consider wrong, as they are only one lane each way in many spots). Twelve Mile Road for example, regardless of having 5-7 lanes is marked at 35 for much of eastern Oakland county and has numerous multi-phase traffic signals.

So I propose we upgrade the Waze road type for all of those big roads to "Expressway". Specifically I am talking about anything that is keyed as a Double-Red and Double-Grey (county-owned divided highways like Metro Parkway and Mound) on the Official State of Michigan Map -- http://tinyurl.com/MIstatemap

Note that looking over the map, I'm fairly confident that despite what the legend implies, the double grey line had an extra standard besides just the road being divided. Example Greenfield though it is divided through Dearborn didn't earn a double -- note it does not have Michigan Lefts nor is it designed for high speed. The entirety of Outer Drive though very wide also didn't qualify it as it is low speed and residential.

[sketch]

We probably should have been more forthcoming about this on this particular subforum, but Michigan, and especially the Detroit area, is a sort of de facto test area for the new road type rules, which are to be the nationwide rules.

The Waze routing server is a complicated thing, but in general Freeways get the highest priority, followed closely by Major Highways; the other types follow behind in descending order. Freeways and Major Highways are the only two types that can be used for any route — for >200 mi routes, anything between the first and last 100 miles must be one of these two types. How they work in shorter-distance routing is not quite so simple — historical and current speed data are used, but road type still does play some significance, and Freeway and Major Highway are still considered nearly the same. In other words, Waze will not hesitate to use a Major Highway instead of a Freeway where the Freeway is backed up — but Waze still uses

Freeways have always been defined as they are now, as Freeways. Expressways are similar to freeways, but they aren't similar enough to merit the Freeway type — someone who wants to use "avoid freeways" presumably wouldn't mind driving on Metro Pkwy. So they must fall into the next type down, which is Major Highway. But not every alternative to a Freeway is going to be an expressway, so other high-mobility roads need to share the Major Highway type to provide viable alternatives to freeways. A two-lane road can still be a viable option, especially in less-built-up areas. (The other types will also be used to provide alternatives, just not as readily, or as heavily.)

Luckily, MDOT has already answered it for us in their functional classification maps. All the Major Highways you see in Waze are classified as "(Other) Principal Arterials", basically, roads that provide the best facilities for traffic but aren't Freeways. It leaves the guesswork out of road typing.

In short: An expressway is not a freeway, but there is no disadvantage to typing an expressway as Major Highway. Waze will choose between it and other Major Highways (and to a lesser extent other roads) using historical and current traffic speed data.

[davielde]

Specifically I am talking about anything that is keyed as a Double-Red and Double-Grey (county-owned divided highways like Metro Parkway and Mound) on the Official State of Michigan Map -- http://tinyurl.com/MIstatemap

Note that looking over the map, I'm fairly confident that despite what the legend implies, the double grey line had an extra standard besides just the road being divided. Example Greenfield though it is divided through Dearborn didn't earn a double -- note it does not have Michigan Lefts nor is it designed for high speed. The entirety of Outer Drive though very wide also didn't qualify it as it is low speed and residential.

That's an interesting point. I've never paid attention to single versus double lines on the state map, but it must be more than just divided highway because there are a number of split roads in other parts of the state--and even within metro Detroit as you point out--that don't "earn" the double line. The presence of signed or even traffic-controlled Michigan Lefts does not seem to be a determining factor from what I can see though.

As sketch pointed out, we're using an "official" state map for functional classification of road types, but it's just not the same "official" map . As you point out with Long Lake and Evergreen, not all of the principal arterials are created equal in terms of what you typically think of as a "major" highway. Some roads that may not appear important still may carry 30,000+ vehicles per day on average though--even if they have a low speed limit or have fewer lanes. They serve an important function but have a meek appearance. Even if I don't necessarily agree with MDOT in all cases, putting the burden of the decision on them and having a consistent standard is worth it in my opinion.

[TeeDee55]

It really seems that more classifications are needed in WAZE to distinguish between all these different roads so that proper priorities can be set in the routing system. We in the Detroit area will be an area crisscrossed with Major Highways every mile. Telegraph Rd, Mound Road, Van Dyke, will have the same classification as the mile roads (many of which are 2 lane roads without even a center turn lane). Or an additional field needs to be added to the system (number of lanes or a number which reflects some of the realities of the number of lanes, amount of grade level intersections- including driveways, etc.) Routing penalties assigned based on the additional field.

[davielde]

I agree that there could be more classifications with different penalties assessed to each, but it is more of an editor consideration than a routing one. Waze would then need to carefully weigh how to consider any potential penalties for the additional road types. A faster route is faster route, so it could be assumed that they would not want to penalize too heavily based on the appearance of the route. From a display perspective though, unless you are using the Map Editors theme in the client app, most of the roads are distinguished only by width or border. Too many classifications would be an issue on the client.

From a routing standpoint, having "principal arterials" mapped to "major highway" only makes those principals available for consideration when planning longer distance routes or detours. It does not mean that Waze will prefer one route over the other based on road type itself. If you have the setting set to fastest route, Waze will pick the faster route regardless of what the road looks like. Same with shortest distance. If 8 Mile/M-102 is faster than 7 Mile/no highway, Waze will still choose 8 Mile. All that having the higher type does is say from the beginning that 7 Mile is available for long distance routes where the relevant segments would be in the middle of the route. It would be discounted based on historic speed or real-time conditions if another stretch is faster, but at least Waze would consider it.