Freeways on maps

[mukade]

Similar to the thread on multi-lane undivided highways...

Similar to the inconsistency in marking divided and other multi-lane highways, the way freeways are marked on maps is not consistent. This is a question on what makes a a non-Interstate highway a freeway for maps. I understand if a DOT would plan to allow an at-grade crossing or a curb cut, it would not qualify, but the assumption is that these would not be allowed. I will focus on Indiana and Illinois, but this applies generally.

There are three parts:

1) Longer and busier roads: Why would certain highways that appear to be fully controlled access always appear as expressways on DOT and commercial maps? Examples:
- The Lloyd Expressway (SR 62/SR 66) in Evansville (once the US 41 interchange is rebuilt, there will be seven or eight consecutive interchanges)
- Illinois rte. 83 (Kingery Hwy) south of "Illinois rte. 110" in the western Chicago suburbs (three consecutive interchanges). I have a hard time understanding why the Nimitz Expy is shown as a freeway and IL 83 is not. IMO, IL 83 is similar to EOE which is marked as a freeway.

2) Shorter sections: What is the minimum requirement for a road to become a freeway? On one extreme, a single interchange or overpass would not make a road a freeway, but would two consecutive interchanges with no at-grade crossings make that stretch a freeway?  Examples:
- Indiana SR 37 in Bloomington (two consecutive interchanges from SR 48 to SR 45)
- US 24 near Fort Wayne (two consecutive interchanges with multiple overpasses from Webster Rd. to the Ohio Line)
- Parts of the Muncie bypass that have no at grade crossings (three consecutive interchanges from US 35 to SR 32)
- SR 49 in Valparaiso (three consecutive interchanges from US 30 up to new interchange at CR 400N)

As a corollary, where would the freeway begin and end? At the first cross street? It should match where the "freeway ends" or "expressway ends" signs if they exist, but these signs are not always put up. Or should it only be shown as a freeway between grade separations?

3) Should a non-state highway with fully controlled access be marked as a freeway?
- Example: Keystone Parkway from 98th Street to US 31 in Carmel

Contrast these to the multiple short freeways shown in northern Ohio, Iowa, Missouri, Wisconsin or roads like M-53 north of Detroit.

Years ago, Cline Avenue (SR 912) in Northwest Indiana appeared as a divided highway on all maps including Indiana DOH even though it had no at-grade crossings north of the Borman. I suggested to the the Chicago Tribune Chicagoland map and Rand McNally that they change it. To their credit, the Chicago Trib map changed it before anyone else, but the whole thing just seems quite subjective. When I travel, knowing a road is a freeway is very useful information so this is an attempt to find an objective and consistent answer.

[vdeane]

Ending a freeway at the last interchange even when it still has full access control to the next cross street is silly; in fact, this is the sole reason I don't use MapQuest (at least with their own data; I will use them with OSM data) any more.

[kphoger]

Ending a freeway at the last interchange even when it still has full access control to the next cross street is silly; in fact, this is the sole reason I don't use MapQuest (at least with their own data; I will use them with OSM data) any more.

I agree.  Show it as a freeway for the entire length of road on which one will not encounter cross traffic.

[Roadsguy]

Google's doing that more and more lately (again), and rarely-updating Bing does that almost everywhere!

[NE2]

I agree with continuing the freeway to the first intersection. But what's one to do where a single intersection separates two freeway segments?

[TheStranger]

2) Shorter sections: What is the minimum requirement for a road to become a freeway? On one extreme, a single interchange or overpass would not make a road a freeway

CalTrans's definitions - and the CSAA maps that were created in some accordance to them - are inconsistent:

- Route 1 between Font Boulevard and I-280 in San Francisco is all freeway (Alemany Boulevard exit, Palmetto Drive RIRO, Brotherhood Way cloverleaf) and yet is rarely ever marked that way on maps and has a "Freeway Ends" sign right after splitting off of 280...

- Route 35 in Daly City has only one interchange, at Route 1, but is signed as a freeway with FREEWAY BEGINS/ENDS signs between two at-grade junctions (Westmoor Avenue & Hickey Boulevard).

---

Another time this comes up is with what I've termed "Jersey freeways" over the years, i.e. Route 17 - interchanges except for shopping center driveways.  Too often these are shown as roads with full at-grades (which they are not) - while they aren't necessarily completely controlled access, they're at a level higher than mere "four lane divided road."

[Duke87]

Google's doing that more and more lately (again), and rarely-updating Bing does that almost everywhere!

I've lately seen a lot of Google having the opposite problem: marking as freeways roads which clearly are not. Extreme example: all of US 22 between Monroeville and Holidaysburg is marked as freeway. In reality, it is all divided, but most of it is not controlled access.

I agree with continuing the freeway to the first intersection. But what's one to do where a single intersection separates two freeway segments?

Mark it as a freeway on each side up to the intersection, just not at it. Like so:


You do need to make sure that your software is able to render this accurately, though.

[NE2]

Mark it as a freeway on each side up to the intersection, just not at it. Like so:


You do need to make sure that your software is able to render this accurately, though.

I'd interpret that as an overpass

[kphoger]

I would do it something like this:

[NE2]

I would do it something like this:

That's what you usually see, but if rendering from a database (e.g. OSM) rather than drawing the map by hand, you need to either make complicated rules about when to render that intersection or cut off the freeway at an arbitrary point before.

[Duke87]

I'd interpret that as an overpass

Hmm... yeah, I see the issue. The difference between an intersection and an overpass in the rendering would be that for an overpass the black lines at the edge of the road would continue across the freeway whereas for the intersection the yellow and blue regions are open to each other with no border between them. But you need enough contrast between the border and the fill so that both are always clearly apparent for this to work. Either the blue in my example is too dark, or the borders are too thin, or both.

Maybe it would help if you used a gradient to fade the blue into the yellow. Then the obvious lack of a hard edge would make it clear that the two roads intersect rather than bridge.

[Bickendan]

You'll still run into trouble if you used Thomas Guide symbology and the single intersection on the otherwise freeway is a minor road and not an artery. The minor road, a black line about 2 pixels thick, will still appear as an overpass. The best solution in that case is to use something like the third example in kphoger's image, but this is Thomas Bros' weak point in the symbology (most evident in the Baltimore TG): Freeways are red. Highways are tan. The two colours can blur, making it hard to tell if that non-Interstate is a freeway (it must be, given all those interchanges...) or not (because that might be minor road at-grade, or just an overpass).