N-scale: Building the 105 freeway.

[Chevron_GATX]

Building modern concrete freeways:

Both BLMA and Rix highway products are simply too small to mimic modern multi-lane freeways, so I think I'm going to attempt to build my own. I think it'll be one of those "cross-section" models where the roadway bisects the layout, beginning with a cross-section at the "front" and ending at the "rear." Southern California freeways are huge, and can be anywhere from 10-14 lanes wide. Both the 105 Century Freeway and 110 Harbor Freeway also accommodate dual-track, light-rail lines in their center dividers, along with single- and two-lane dedicated HOV lanes.

Here's a proto picture of the 105 freeway I've posted previously:

Photo by Darrell Clarke.

Materials:

I just bought some BLMA N-scale K-rails which I can use for the center divider. The concrete sides of the freeway, I was thinking to possibly kit-bash some Kato viaduct track. I'll just pull the track, saw the viaduct in half, and paint appropriately.

For the concrete supports, the Rix product's model design should be easy enough to replicate from stock styrene. I may use extruded aluminum for the roadbed base to prevent any sort of warping, then adhere some other substrate (e.g., Foamcore, styrene, etc.) painted with the correct hue of latex paint (aptly weathered, of course) for the roadbed itself. I'll probably use matte vinyl graphics tape for road markings. This is the one thing I really want to get right, which so many off-the-shelf roadways often get so wrong. The road markings will be as close to prototype as possible, and on this particular freeway, there are many, and very specifically varied. Even CalTrans can't maintain a consistent marking style for demarcating their HOV lanes: Sometimes they're a pair of double-yellow lines; sometimes, they're a pair of solid white lines, etc.

For me, this would be an ambitious project, since my modeling skills aren't very advanced (I spent quite a while just trying to apply some simple water-slide decals to my SP locos last night). But I've always loved the way freeways look, and when done well in other modelers' layouts, they often bring an immense amount of realism to the layout.

 

[santafewillie]

Ambitious project to say the least. Consider this, in "N" scale, 6 lanes at 12' (5 regular + 1 HOV) = 5.4", add 2 shoulders (one each side) of 10' @ = 1.5" and a 30' ROW for the track = 2.25" now gives you 9.15" for each side of the freeway, or 18.3" for the whole thing in "N" scale. If there are service roads (or frontage roads) on the side to go with that, add some more for them as well as the space in between the freeway and service roads. 2-HOV lanes on each side will be an addition. A lot of real estate. I am not trying to dissuade you, but realize the scope. That's why one rarely sees actual freeways modeled on layouts.
Just saying...

Willie

 

[OldGuyHO]

Remember the phrase "selective compression". But if you want to model it, it's your railroad.

 

[Chevron_GATX]

Ambitious project to say the least . . . A lot of real estate . . .

Thanks for your reply, and thanks for doing some of the math. Yeah, I know it's gonna be big. I wish I could model it so that it sits in the layout laterally (e.g., 12' across the entire layout) instead of just a cross-section. When I get a chance, I'll take more proto photos of the freeway (easily accessible from Imperial Highway underneath), and actually measure its width using a DSLR (EXIF data contains rangefinder-focus distance). There's even an active surface-rail route which goes under the freeway at this point (at the intersection of Imperial Highway and Aviation Blvd. in Los Angeles, near LAX).

 

[Chevron_GATX]

Remember the phrase "selective compression". But if you want to model it, it's your railroad.

Thanks for your reply. I struggled bit to find a succinct definition of selective compression, but I think I get the idea. I suppose it's different than forced perspective (which I won't be using), but doesn't necessarily exclude that from being a component of a selective compression technique.

 

[Chevron_GATX]

 

[Chevron_GATX]

I think I might use some all-thread rod to use as the supports, since I can use nuts on the thread to attach the rods to the extruded aluminum road-base. Then I suppose I can sheath the all-thread with some styrene tubing (then paint accordingly) to make it look like concrete. Then, perhaps I can precision-cut some dimensional lumber to use as the concrete bases (the rectangular-ish forms). I could also look into kit-bashing some off-the-shelf concrete piers. With the right paint, scoring, and weathering, hopefully, everything should look like poured concrete.

I can't find any more BLMA K-rails to buy (I could only order one package of 12), so I may have to use some gray vinyl wall base that I have left over from a bathroom remodel. If I cut it near the edge, the product sort of has the form of a K-rail already, but unfortunately somewhat over-scale:

 

[Chevron_GATX]

I was initially planning to do just the freeway, but I may go whole-hog and actually try to model the Metro light-rail line in the middle as well. I could probably even integrate an off-the-shelf Kato train station, and come reasonably close to what the actual Metro station platforms look like. This mock-up is a bit too wide for scale, plus I'll be painting the Foamcore (or whatever I end up using) a light-gray, and hand-ballasting the track on the final version:

 

[Chevron_GATX]

 

[Chevron_GATX]

The 105 is actually one of the smaller-width freeways in Los Angeles. Also, additional lanes appear and disappear along its route. This section appears to have only three regular lanes plus one HOV lane. So let's say it's an eight-lane freeway, including the HOV lane and its larger demarcation area. If I'm going to model a station, I noticed that the tracks and the freeway do widen a bit to accommodate the width of the station (this goes largely unnoticed when actually driving on the freeway). Also, I may model this laterally within the layout and only model one direction of travel.

So, using this as just a starting point, that's four 12'-wide lanes, plus the additional margins for the HOV demarcation and the apron. To accommodate two rail lines, I'm not sure what that dimension is, and I'm unsure if I can just double your ROW figure of 30'. Let's say a 12' lane is 0.9" at-scale. Starting with a single-rail figure of 30' (2.5"), I'll add four lanes (3.6"), HOV demarcation (0.4"), and the apron (0.9"), totaling approximately 7.5" for one-half of the freeway.

 

[Jim 68cuda]

Using "selective compression", you could probably cut down the lane width. Instead of a scale 12' wide lane, a scale 9' or 10'wide lane would probably look correct since federal regulations pretty much limit vehicle width to 8' on federal highways.

 

[Chevron_GATX]

 

[Chevron_GATX]

Above, I decided to just cut some 3/4" melamine and spray-paint it primer gray. I attached a length of 1" extruded angle-aluminum for one side with silicone caulk (I ran out of material to do the other side). I'll have to rout-out the center of the melamine so that the Kato dual-track sets into the roadbed a few scale-feet below the road surface. Later I can add some Kato Unitrack ballast to fill-in any gaps. I think I can just use wooden dowels for the concrete piers, then attach them to the melamine with some counter-sunk wood screws (which will be patched and painted).

Tomorrow I'll try to cut some gray vinyl cove-base to attempt to make the K-rails which divide the traffic lanes from the railroad ROW. I'm still waiting for my stupid vinyl graphics tape order to be filled to make the road markings. I should get more Busch and Kato N-scale vehicles tomorrow.

 

[Chevron_GATX]

Using "selective compression", you could probably cut down the lane width. Instead of a scale 12' wide lane, a scale 9' or 10'wide lane would probably look correct since federal regulations pretty much limit vehicle width to 8' on federal highways.

Yeah, I thought 12' looked a bit wide (0.9"). I'm going to try to measure the actual lanes on the 105 somehow. I still want to try to produce this at-scale. That'll be eight lanes, including two HOV lanes, plus the two Metro light-rail railroad tracks. I did some scale calculations, but if it still doesn't look quite right, I'll just cut another piece of melamine a little narrower or a little wider until it scales correctly with the Busch 1:160 scale vehicles.

 

[Chevron_GATX]

I should probably do this "right" and get the Kato V15 Unitrack kit for platforms, and integrate an elevated station, as the 105 freeway actually has:

Using possibly this Kato platform:

 

[Chevron_GATX]

 

[Chevron_GATX]

From CalTrans' site: How wide are freeway lanes?

" . . . An eight lane freeway would consist of an outside shoulder, four travel lanes, an inside shoulder and then on the other side, lanes going in the opposite direction, would be the inside shoulder, 4 travel lanes and an outside shoulder. Outside Shoulders are generally 10' 4 lanes of travel way are 48' (12' per lane) Inside Shoulders are 8' So overall an eight-lane freeway would be 132' wide on an average. Inside shoulders can vary from 5' to 8', Outside shoulders can vary from 5' to 10' and travel lanes depending upon the type of highway can vary from 10' to 15'."

 

[Chevron_GATX]

 

[Chevron_GATX]

Now, to model the supporting piers. I found a good visual reference here. The 'T' type "hammerhead" piers are quite common in Southern California as freeway supporting structures; however, the more modern piers are actually hexagonal and not cylindrical. Although I was planning to run to Home Depot to buy some wooden dowels, the 'T' type pier is actually more prototypical, though I could use the dowels, if choosing to model a "cap-and-column" style pier instead. An interesting modeling detail, if doing a cap-and-column pier, would be to add the metal sheathing which has been applied to all California cylindrical piers for improved earthquake-resistance.

If doing the 'T' type piers, as it happens, Kato's off-the-shelf double-track piers are fairly close to the 'T' type piers:

However, I was planning for the freeway cross-section to fly over another section of viaduct track which is already elevated to this height (2"), using the same piers. I suppose a kit-bash approach to doubling the height of the Kato piers would work if I can figure out a clever way to join two or more piers to gain the additional height.

 

[Chevron_GATX]

I just stumbled upon flyingtiger's very authentic "virtual layout" thread. For reference, I've re-posted his very-proto looking modern concrete freeway: