Roads and Highways


Japan is fairly well-known for small cars, and for having limited space. That, combined with a city that grew up from feudal times when travel was almost exclusively by foot, results in Tōkyō (and other Japanese cities) having extremely small streets. While major roads have lane widths of 3m (10’) to 3.5m (11’ 6”), side streets are often just wide enough for one small car. Tōkyō’s expressways are largely built with 3.25m (10’ 8”) lanes. For comparison, the standard U.S. lane width is 12’ (3.66m), and modern European motorway lanes are around 3.5m (11’ 6”) to 3.75m (12’ 4”).

See the Street Scenery reference images page for examples of many of the things described here. Also see the Buildings Etc. reference images page for some examples of parking arrangements.


Road Sizes and Basic Markings


A major avenue of two lanes each way would thus have a width of 12m (39’) to 15m (49’), not counting median and sidewalks or shoulders. In Japanese N-scale, this equates to a width of 80mm to 100mm, or from 3 1/8” to 4”. However a two-way side street could easily be less than 5m in width, or 33mm (about 1 5/16”) in N-scale, and judging by photos, even narrower ones are common. One-way side streets are common, and need only be as wide as a car (about 2m, or 13mm in N-scale, around a half-inch).

Typical urban two lane (one each way) expressways have a shoulder of 0.5m, for a total width of 7.5m (24’ 7”). In N-scale, this equates to 50mm (2”). Newer expressways use 3.5m lanes, and the Bayshore expressway adds a 2.25m (7’ 4”) breakdown lane, but that is apparently not a common feature; looking at Google Earth views of Tōkyō, limited-access roads appear to have periodic “pull-off” areas to handle disabled vehicles, but not continuous breakdown lanes.

On-street parking is prohibited if there would be less than 3.5m clear to the right of the parked car (i.e., if the width of the road minus the car is less than 3.5m). A marked parking space (in a commercial lot) of 2.3m x 5.0m (7’ 6” x 16’ 5”) is considered “ample”. In N-scale that’s 15mm x 33mm. Most private parking spaces are probably smaller than that.

I’ve done a fair amount of research using Google Earth to examine and measure roads in Tōkyō, primarily in the Koto and Sumida wards, since those are one major reference for my modeling. This is an area with a mixture of two-story residences with larger commercial avenues flanked by multi-story buildings, as well as some large multi-story hotel and residential complexes away from the avenues. Intermixed with all of these are, as is common in Japan, small businesses and industrial companies operating out of one and two-story buildings, and businesses located on the ground floor of a residence or a three-story (or sometimes more) residential building. This makes for a complex set of alleys, lanes, streets and roads where you can see a variety of solutions to the problem of providing vehicular access and parking.

Roads are typically marked which white lines at the edges and between lanes, with solid meaning “do not cross” and dashed lines allowing passing, although yellow is used in a few places where a more absolute prohibition exists (e.g., to prevent turns). Solid white side lines still permit parking, although curbs will be painted orange/yellow as an additional prohibition. On smaller roads, the lines may be omitted, particularly if the edge is already marked by a sidewalk with a railing (but not always), and in alleys often one or both lines are omitted although there may still be vehicular traffic. Parked cars routinely intrude over white lines into the first vehicular lane, and sometimes marked parking spaces are within the lane. However permanent obstructions (electrical poles and similar) will be outside the line even if they are in the road surface.

One important take-away is that lane widths will be variable even on the same street, adjusting as they approach or move away from intersections. Often a road will have two lanes on one side and three on the other at intersections, and these swap before the next is reached; in those cases, the two are typically wider (each) than the three.

Here are some typical lane widths based on that:

Bi-directional road w/ side lines but no centerline: 4.9 m between lines
Two-lane road, no parking: 3.8 - 4.0 m / lane
Two-lane side street: 2.4 m / lane or 2.7 m / ln (two examples)
Large two-lane side street: 4.3 + 4.8 m
Avenue with 7 lanes at intersection: 2.4 - 3.1 m (4 ln) + 3.1 - 3.7m (3 ln)


Road Markings


In addition to the use of lines described above, there are a number of typical roadway markings. These are often similar to those used in other countries, but not identical.

The road will be painted in a dark red color to emphasize a need for caution. This is often used on lanes approaching a busy intersection (but not always). When used, it may be applied only to a turning lane, or a lane shared with a bus stop, or it may be applied to both/all lanes traveling in the same direction. In some smaller intersections, the entire intersection is painted red in lieu of other markings, or the edges of the intersection are outlined in red.

Smaller intersections will not have cross-walks or stop lines, but will typically have a white mark in the middle of the intersection denoting the directions from which traffic can enter. This is thus either a “+” or “T” marking.

While crosswalks are normally formed of parallel white markings (with or without white lines denoting their edges), pedestrian ways alongside roads that use the roadway surface will often be painted in green to indicate their use. This is particularly common at railway grade crossings where there is usually no separate sidewalk.

Parking spaces, if marked, will be denoted by an enclosing rectangle of white lines, with space between each rectangle (presumably to enforce spacing between vehicles). Bus stops will be marked by a large rectangle of white lines, and at the ends triangles filled with white diagonal lines mark “keep clear” areas for the bus to pull in and out.

Within traffic lanes, several markings are common:

- Before a stop line on a side street, the letters “⽌まれ” (To-Mar-Re) are often found, written vertically, spelling out the Japanese word for “Stop”. In some places the English word “STOP”, written horizontally, will be used instead (this seems more common in parking lots).

- Additional writing, in white or rarely in orange/yellow will be seen. Street markings are generally in Japanese written vertically, although some parking lots use “IN” and “OUT”.

- At intersections, white arrows will be used to indicate permissible directions of travel. These have a longer and thinner look than those used in the U.S.

- Approaching a crosswalk, two stretched white-outline diamonds will appear in the lane, these are typically 19 - 20 m apart, with the last 25 - 30 m before the crosswalk, although where space it tight I’ve seen these as close as 15 m to the crosswalk. If the road is too short, a single diamond 25 m before the crosswalk may be used instead.

- Speed limits will sometimes be painted on the road surface as a two-digit orange/yellow number within each lane.

- Restrictions (like “no U turn”) will be marked with a large “X” followed by an arrow (turning or in a U), both in orange/yellow.

- Restrictions can be qualified by time-of-day, written horizontally before the “X” (e.g., “8 - 20” means 8 AM to 8 PM), also in orange/yellow.

- Streets will sometimes have crossing lanes for bicycles adjacent to crosswalks. These are a clear area marked at the ends and in the middle with a picture of a bicycle, accompanied by writing. On the sidewalk at each end may be a bicycle enclosed in a triangle with writing, which I think means “Bicycles stop before crossing”. I’ve also seen a bicycle enclosed in a triangle next to a stop line on a side street intersecting a larger one, which I think means “bicycles must stop too”.

- Manholes within the street are sometimes, but not universally, circled with either white or orange/yellow (white seems more common in intersections, orange/yellow in roads). In particular I’ve seen some large rectangular plates so marked in Koto ward, where nearby circular manholes were not. Access plates located in the gutter at the edge of the road (often for water shut-offs) are not so enclosed.

Note: the color described as “orange/yellow” above is distorted in Google Earth imagery. From street-level photographs, it appears more yellow, approximately RGB 229, 164, 40 (E5A428 in hex). The red used as a tint for warning areas appears to be RGB 136, 105, 107 (87696B in hex). Green I’m less certain of, although it may vary. I found one reference at RGB 60, 140, 130 (3C8C82 in hex) which might be too light, although it looks close.


Lighting


Real city streets have lots of lights, including streetlights and traffic lights (not to mention lights illuminating signs, back-lit signs, and of course lit buildings). But streetlights themselves are a significant characteristic of a road. On an expressway, lights will be on tall special-purpose poles, often with multiple light fixtures, designed to illuminate a wide area. On an urban street lights are smaller, and often mounted on the same poles that carry utility lines. But separate lights may be used in parking areas or to illuminate areas that don’t get enough light from the usual streetlights.

For modern cities, Google Earth (optionally with Google Maps) with streetview is a really useful tool. I used this when designing my elevated highway, based on a Tōkyō prototype that has light poles with two fixtures in the median about 100 feet (30 m) apart. However, away from a highway, light placement is at least partially controlled by other features (such as illuminating intersections, pedestrian crossings and similar things). Google Earth doesn't work as well in suburban and rural areas because the photographic resolution away from cities may not be high enough to locate the poles in satellite view.

The process I use is to find a street of the desired kind that is well-lit by the sun (i.e., not shadowed by buildings) in satellite view. Then use Streetview to identify where the light poles are (it's hard to separate light poles from other kinds of poles in satellite view). Now that I know where the poles are, I use satellite view and the ruler (which only seems to exist in Google Earth, not Google Maps) to measure the distance between the bases (you can often follow the shadow of the pole to find the base). I repeat this for several poles to get an idea of the variation in spacing. I like to use Google Maps for streetview and Google Earth for the ruler, switching between the two as needed.

Note that in some cases a light will be closely mounted to an electrical pole (and only visible in streetview), in others it will be on a boom placing it over the street (typical around crosswalks, but I've seen both kinds both with and without them). There are also standalone light poles, used where a light is needed away from an electrical pole.

I picked a representative large multi-lane avenue in Sumida ward (Yotsume Dori, south of Kinshicho station), and found roughly one light per block at a spacing of around 120 feet (37m) near a major intersection (which was likely well-lit by department store lighting), but at two blocks away this seemed to switch to about 80 feet (24m). What seemed to control the spacing was a desire to have either one mid-block (between major roads) or one at each end of a block (one at each intersection). In some cases this ended up with one on both sides of a large intersection (just above the crosswalks), but others did not have them at crosswalks (there may have been small close-mounted ones I just couldn't spot in the tangle of wires).

Then I went down a small side street (one lane each way, not a 1.5 car micro street). This had a light at each intersection, and two opposite each other mid-block, which worked out to spacings around 40 - 80 feet (~12 - 24m) on alternating sides. However, near one end of the block was a small alley (literally only wide enough for a scooter) which had a pair of light poles in the alley, perhaps 12-15 feet (4-5m) from each end, one of which was fairly close to the light in the street (which was at enough of an angle it didn't illuminate the alley). A second alley (wide enough for one car, and possibly a street) had one light at each end, inset similarly from the larger street. Note that all of this was essentially a commercial district, with stores, apartments and parking garages. An interesting detail is that the standalone poles appeared to be metal, painted bright orange, where the utility poles were the typical concrete ones (an unpainted gray color).

Then I picked a small urban residential street (one way, one car wide, lots of two-story multi-tennant buildings). It had a light at the end meeting a larger two-lane road (the intersection had at least three lights close to it actually). The one on the side street was a small rectangular fixture mounted close to the pole above a crosswalk, and was probably rather directional. Down the street there were lights mounted on each electrical pole (some close, some on a short boom), but no standalone ones. The electrical pole spacing was mostly 60 feet (18m) with one 110 foot (33m) spacing, but there may have been a pole midway between with a light (streetview cut the top off some kind of pole on the opposite side of the street from the others next to an alley and that corner was in shade in satellite view so I couldn't tell what it was from there).

So there's a lot of variation. Intersections should be well lit, typically with more than one pole (up to four for larger ones) either at or very near them, mid-block lights may or may not exist. Spacing for tall standalone poles can be quite large (80 - 120 feet, or 24 - 37m), but can be closer where warranted. Smaller lights can be more closely spaced, particularly if buildings create shadowed areas that need a second light to illuminate them (and have reason to be illuminated).

For modeling purposes, spacing should also depend on the area the light actually illuminates and the impression to be conveyed. Should there be dark areas between pools of light (more typical for residential neighborhoods and office areas) or continuously illuminated streets (more realistic for a shopping district)?


References



Progress Report on Next-Generation Infrared Beacon in Japan, Yasushi MORI, Nobuhiro HAMBA, Universal Traffic Management Society of Japan (UTMS) (PDF)
technical paper on road-vehicle communication systems that notes typical lane width.

Tokyo’s Slim Expressways, posting on Tollroadnews.com, reprint of a July 1996 article.

Road Signs in Japan, U.S. Navy Publication (PDF) (this site has a bad security certificate, which will generate a warning if you try to access it, but Firefox, and likely other browsers, will allow you to add it temporarily).

Driving in Japan, U.S. Navy Publication (PDF)

Good Parking System, from the Japan Parking Facilities Promotion Organization website.
a checklist for evaluating Japanese parking lots.

Trans-European North-South Motorway (TEM), TEM Standards and Practice, 3rd Ed., 2002 (PDF)