Friday, March 30, 2012

Vehicles for roads, streets and country roads

I've long appreciated the distinction that Chuck Marohn has been making between roads and streets, and I'm glad he's added country roads to the mix. Chuck has pointed out the problems that arise when we try to treat streets or country roads like highways, and when we try to treat highways like streets. A lot of that, and a whole lot more problems, come from the vehicles we use to navigate those different ways, specifically from trying to use road vehicles on streets and country roads, and vice versa.

As Chuck says, a road is for long-distance travel, and it functions most efficiently at maximum speed with the minimum number of intersections. A street is a place for commerce and other social activity, including local travel, and it functions best at low speeds with lots of connections to other streets and spaces. A country road is for medium-distance travel, and it functions best when no one is trying to use it as a highway or street.

The most efficient vehicles for moving things on highways are trucks, and the bigger and faster, the better. The most efficient vehicles for moving people on highways are "over the road" buses, the high floor kind with one door at the front. If you don't care about the costs to yourself or others, a sports car is the most effective way to move people (yourself and maybe one other person).

The most efficient way to move things in streets are the various slow-moving human-powered strategies: backpacks, pushcarts, hydraulic-assisted forklifts. Which strategy depends on the size of the things. The best way to move people in streets is on foot or wheelchair.

The best way to move things or people on a country road is a pickup truck.

A lot of the problems we have on streets (as in places for social activity) come from people using trucks, sports cars and big buses on them. They are big, heavy and hard to maneuver, and we wind up killing people when we try. People have tried various strategies to compensate for this, but none have worked very well.


Mike Hicks said...

Yeah, I feel that semi trucks are the worst offenders and probably do the most to explain the absurd intersections we've gotten over the years. 53-foot trailers are pretty damn difficult to maneuver without banging into something and are guaranteed to climb over curbs and sidewalks at corners. Ideally, I'd like to see deliveries in town happen with smaller vehicles, though that's clearly less efficient.

christine said...

Good to see that you agree with @CHEKPEDS " A lot of the problems we have on streets (as in places for social activity) come from people using trucks, sports cars and big buses on them. They are big, heavy and hard to maneuver, and we wind up killing people when we try."

It is even worse when these buses carry illegal weight ( over 36,000 pounds), when their drivers are unlicensed or when they get lost , use they portable GPS and kill four of their passengers. DNA info has good articles about that.

WE love buses because it is 50 less cars. But they must respect the rules of the road and there need to be planning on how to accommodate them ...

In Hell's kitchen there are 8,000 buses daily on our residential streets, idling for hours at a time. Bloomberg administration is still focused on building parking for private cars , but no one is focusing on parking and terminals for buses.

Do not sign the petition it if you do not want to but stop using tweeter to attack my petition and call me names : NIMBY? I have convinced our Community Board and the DOT to add 47 curbside parking spots right in our backyard.
Alternatively you can go to and we can have a meaningful conversation.
See ya at the next TA party....

EngineerScotty said...


neroden@gmail said...

Country roads are important.

But I'm not sure what to do with them. Making them gravel or dirt certainly seems monetarily appropriate,... but it's actually awfully hard to maintain. Our cars are no longer designed to drive over dirt with massive potholes.

There's gotta be some way to make country roads durable enough that they won't denegerate into mud quickly, while making them inherently slow.

EngineerScotty said...


The way you describe roads is as a primarily rural phenomenon, designed to connect cities rather than run within them. (Your reference to coach-style rather than transit-style busses is a giveaway--motor coaches are optimized for point-to-point trips where everyone boards at one end and disembarks at the other, rather than the continuous off and on of transit).

Given that, were one do a 2x2 graph containing different types of thoroughfares, with one axis being mobility/access and the other being urban/rural, we'd have the following:

Rural, access: Country roads
Rural, mobility: Roads
Urban, access: Streets
Urban, mobility: ?

There's a quadrant missing.

Roads (as defined here), in the city, are generally a bad thing. If not grade-separated, they dismember and destroy neighborhoods, as they are a major impediment to cross-traffic (particularly of non-motorized vehicles and pedestrians). If you grade-separate them, they still are a blight no the landscape. Burying them in tunnels seems to work, but that's expensive.

But we still have need for intra-city mobility of the sort that cannot be accommodated with streets alone. Even if SOVs were banned, trucks and busses still need some way to get around to serve medium-distant trips. Cities need arterials of some sort to function.

While there are many designs for (at-grade) urban arterials that don't work--quite a few types of stroads, there are a few that seem to work reasonably well. I propose the name Boulevard for such a creature:

What are the attributes of a successful boulevard?

* Frequent signalized access points, so cross traffic is not un-necessarily impeded, and traffic is calmed.

* Cross traffic permitted every block, even where there is no light. RIRO-style access (or LILO in left-hand-drive countries) makes a thoroughfare look like a highway.

* Extensive use by transit, either in a dedicated lane or mixed-traffic. (The former helps with mobility, the latter helps with traffic calming). No bus pull-outs.

* No more than 3 general-purpose lanes per direction, and preferably no more than 2. (Anything wider and the thing starts to resemble a highway. Queens Boulevard is the extreme example of what happens when you make an urban thoroughfare too wide).

* Designed for speeds of no more than 30MPH (50 km/h) or so.

* On-street parking or loading, to further calm traffic and provide a pedestrian barrier.

* Median pedestrian refuges as needed to facilitate safe crossings, but no continuous medians (unless used for a busway). Continuous medians make streets look like highways.

One reason Portland, I think, is a good pedestrian city--beyond the ample pedestrian-specific infrastructure, is many of the city's arterials are Boulevards as described above (other than the lack of dedicated busways and such). SE Powell, NE Sandy, NE MLK, and numerous other thoroughfares in the city which are signed state highways are built to the above Boulevard standard, and have thriving pedestrian neighborhoods (and excellent transit patronage) along them. The six-lane divided sprawlterial, where cars get up to 50MPH between lights before slamming the breaks at the next red, and which pedestrians cross at their own extreme risk, is actually quite rare in Portland. (It's more common in the suburbs, but even there, Portland's suburbs are nothing compared to places like suburban LA or Phoenix for sheer numbers of quasi-highways carving up cities into discrete squares).

EngineerScotty said...

A couple other thoughts on country roads, coming from someone who grew up in the countryside.

* A key concern of country roads is the movement of farm machinery. Such equipment generally has no problems with unpaved surfaces, but frequently needs a rather wide right-of-way.

* An excellent "vehicle" for medium-distant movements in the countryside, especially if no freight is being moved, is the horse. Horses are unsuitable in the city for numerous reasons (need lots of space and feed, easily spooked, and the problem of horse poop), but are well-suited to rural environments, and likewise don't need well-maintained roads to be useful. Horse-drawn wagons and farm equipment aren't very common now--engine-powered vehicles are better suited to hauling, harvesting, and plowing--but as personal transport, horses are a great option in the country. (Substitute other draft/pack animals as necessary, though the riding of oxen appears to be a lost art in the US, and donkeys/mules are generally used for specialized applications).

neroden@gmail said...

"Urban, mobility: ?

There's a quadrant missing."

Grade-separated railways.

Precisely the point of transit advocacy is that roads are no good for urban mobility. Railways take up less space and move more stuff faster within the same space; railways are what you need for urban mobility. Urban freight mobility is especially tricky and demands the occassional intermodal truck-to-train transload yard.

Cap'n Transit said...

Yes, Neroden, I tackle that in my next post.