Greater Greater Washington

Montgomery's fake cul-de-sacs don't solve traffic woes

Concerned about through traffic, many neighborhoods in Montgomery County have closed off their once-connected streets. But the costs of a quiet street might outweigh the benefits.


Sign on Ellsworth Drive outside downtown Silver Spring. Photo by the author.

Montgomery County neighborhoods, like many in North America, generally fall into two categories: those with cul-de-sacs, and those without. Before World War II, and for a little while afterwards, neighborhoods in Montgomery were built with streets in a grid, or at least in a connected network. As cars became more popular, these streets often became noisy and congested, so planners came up with an alternative.

With support from the Federal Housing Administration and prevailing design trends that turned their back on traditional urban street patterns, builders nationwide switched to cul-de-sacs. As a result, most Montgomery neighborhoods built since then have them. Just look at a map of the county and you can pick out older, gridded communities like Bethesda from newer ones with loopy, disconnected streets, like Germantown.


Disconnected cul-de-sacs in Germantown force everyone to use collector roads. Photo by Evan Glass.


Gridded streets in King Farm disperse traffic throughout the neighborhood. Photo by Evan Glass.

Of course, cul-de-sacs weren't the traffic panacea 20th-century planners thought they were, and there's since been a growing backlash against them. In some newer neighborhoods like Poplar Run in Glenmont, they're few and far between; in others, like Kentlands in Gaithersburg or King Farm in Rockville, they've been all but banished.

We've returned to appreciating a connected street network, which can diffuse congestion and make walking, biking and even driving safer and easier. They're also cheaper to maintain and easier for emergency vehicles to navigate, which are two of the reasons why Virginia banned cul-de-sacs in 2009.

Yet in many of Montgomery's oldest neighborhoods, which were built with grids to begin with, the cul-de-sac mindset remains. Prodded by residents sick of speeding drivers on their neighborhood streets, the county's Department of Transportation has found ways to keep through traffic at bay using a kind of "fake" cul-de-sac.

Sometimes, they'll restrict turns from arterial streets or ban cars from entering certain streets at rush hour. Occasionally, they'll take more drastic measures and cut off a through-street entirely, like Ellsworth Drive near downtown Silver Spring.

If you live on a street like Ellsworth, you're probably not complaining. You get all of the benefits of living next to one of the region's biggest jobs, shopping and entertainment districts, while enjoying quiet, peaceful streets undisturbed by people from outside the neighborhood.

Less amused, however, are your neighbors on adjacent streets, like Colesville Road, Wayne Avenue or Georgia Avenue, that have to pick up the slack. Breaking up the street grid means more local trips end up on what through streets remain, making them more congested.

Studies show that residents living on busy streets are not only exposed to higher pollution levels, but they have fewer friends and a weakened sense of community.


Cutting off through-streets in Silver Spring forces all traffic onto streets like Georgia Avenue, making them a barrier between neighborhoods. Photo by the author.

Sometimes access restrictions displace car traffic to another neighborhood entirely. In 2010, the Sligo Park Hills community in Silver Spring asked the county to restrict rush-hour commuters from using several streets there.

Neighbors in adjacent Takoma Park worried it would just send cars their way. "We will be impacted by moving your traffic over to us, and your neighborhood is no more important, your kids are no important and your convenience is no more important [than our own]," said Takoma Park resident Ellen Zavian.

However, one Sligo Park Hills resident was so tired of drivers using his street that he threatened violence against them. "If you guys drive through my neighborhood in the early morning hours and I perceive you to be a threat, I'm going to start walking around with a rock in my hand," Sean Gibbons told the Gazette.

As a result, the City of Takoma Park implemented their own traffic restrictions later that year. Mayor Bruce Williams said that if they didn't, they would "be essentially saying 'okay take all that traffic and send it through Mississippi Avenue and Ritchie Avenue."

We can't fault people for wanting to live on a safe, quiet street, but the streets in neighborhoods like Sligo Park Hills are owned by Montgomery County, meaning that all Montgomery County residents pay taxes to maintain them, and have a right to use them. Besides, telling drivers they can't use your street does nothing to solve the larger traffic problem.

If we're trying to discourage folks from driving through certain neighborhoods, we might as well finish the job and make it easier for them and the people living in these neighborhoods to get around without a car.

While Montgomery's older communities were built with interconnected streets, they didn't have sidewalks. Many residents want to keep it that way. However, the best way to reduce car traffic, at least for shorter trips, is to make it easier and safer to bike or walk. Many of the neighborhoods that currently have traffic restrictions are already within a short walk or bike ride of major shopping areas, job centers and public transit. If more people are out biking and walking on local streets, it'll be a cue that drivers should slow down.

Sidewalks are a start, though Montgomery County planners have also explored striping a "pedestrian lane" on streets where sidewalks are either impractical or too costly. While we're at it, we could stripe some more bike lanes as well.


Bike Boulevard in Berkeley, California. Photo by Artbandito on Flickr.

Or we could turn streets like Ellsworth Drive into "neighborhood greenways," also known as "bike boulevards," designed to give people on foot or bike priority over drivers. That's sort of what currently exists on Second Avenue between 16th and Spring streets in Silver Spring, which allows bikes and buses during rush hour, but not cars. And if we're going to turn a street into a dead-end, we should at least make it passable for pedestrians and bicyclists, like on Middleton Lane near downtown Bethesda.

A well-connected street network has many potential benefits: better access to local amenities, diffused traffic congestion, and even stronger social ties. The best way to reduce congestion on little streets and big streets alike is to give people choices, whether it's multiple routes for driving, the option of taking transit, or the ability to safely get around by foot or bike.

While residents shouldn't have to worry about speeding drivers or heavy traffic on small neighborhood streets, closing off public streets isn't a real solution.

Dan Reed is an urban planner at Nelson\Nygaard. He writes his own blog, Just Up the Pike, and serves as the Land Use Chair for the Action Committee for Transit. He lives in downtown Silver Spring. All opinions are his own. 

Comments

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"Besides, telling drivers they can't use your street does nothing to solve the larger traffic problem."

Uh, yes it does. It is called induced demand. More street space means more traffic, less means less.

Also, urban arterials can also be traffic calmed.

by Paul H on Jul 31, 2012 12:22 pm • linkreport

Dan

great article, as usual, but one quibble

Va never banned Cul de sacs. They insisted every subdivision have at least two entrances, to the whole subdivision can't be a cul de sac. But individual small cul de sacs within a subdivision were never banned.

by AWalkerInTheCity on Jul 31, 2012 12:28 pm • linkreport

@paul

Im not sure that having more connectivity is going to lead to that many more VMTs' For one thing, induced demand often means folks going far instead of a closer destination. lack of connectivity disproportionately impacts short auto trips compared to long ones (think about it). I also doubt its important enough for long trips to enable sprawl. third, the impact of non-connectivity is particularly great on cyclists and pedestrians.

Even if you like road congestion as anti-sprawl or anti-VMT strategy (and I think there are a lot of cons to that approach) lack of connectivity seems about the worst version of it.

by AWalkerInTheCity on Jul 31, 2012 12:37 pm • linkreport

I have never understood why they don't enforce speeding laws on residential streets: at least I've never seen it done. You could even deputize local citizens.

by SJE on Jul 31, 2012 12:51 pm • linkreport

Paul, you can only reduce demand if you give people viable alternative options-- a point which Dan touches on. If you constrain traffic by adding more choke points, it's very possible that the volume of traffic stays the same while flow decreases.

by tresluxe on Jul 31, 2012 12:53 pm • linkreport

"You could even deputize local citizens."

Yeah, if there's one thing this region and nation needs, it's more George Zimmermans.

by Kolohe on Jul 31, 2012 12:53 pm • linkreport

Great post. It's a "I got mine so the hell with you" mentality that's turning once contiguous neighborhoods into gated communities. While I have no sympathy for those who complain about traffic while chosing to live 100 miles from DC, it's unfair to choke off the closer in neighborhoods to thru traffic. It's especially ridiculous when they build permanent barriers that can't be circumnavigated during power outages and other emergancies. If you live in the center of a city, you get the benefits and the inconveniences.

by Thayer-D on Jul 31, 2012 1:01 pm • linkreport

I love the continued war on single family neighborhoods from this blog, especially the posts by those who don't live in the County most of the time, don't own property here and think we have endless pots of money to retrofit everything to fit THEIR vision of what they want.

by kct on Jul 31, 2012 1:07 pm • linkreport

Has anyone done a study on how to best undo cul-de-sacs? A bit late now, but it would probably be possible for a foreclosure program to resell properties but reserve pedestrian easements. That's now free, but still it would avoid the cost of trying to actually buy an easement.

by JimT on Jul 31, 2012 1:12 pm • linkreport

Typo: I meant "that's not free.."

by JimT on Jul 31, 2012 1:12 pm • linkreport

Great article with lots of great points.

We're seeing this more and more in DC as well, particularly in places where the residents of these 'Ellsworth Drives' have the capital to push through such restrictions.

You also see echoes of it in the complaints about the Wisconsin Avenue streetscape project in Glover Park, where there are complaints that streamlining Wisconsin will result in non-residents using side streets. Also, of course, in the Georgetown neighbors' insistence on removing University buses from "residential" streets.

This really is one of those key philosophical differences. Either you believe in a complete street grid or you believe that traffic should stick to arterials and side streets should be for residents only. There's space between the two, but at its core, you're talking about two fundamentally opposed views of urban layout.

by Dizzy on Jul 31, 2012 1:16 pm • linkreport

Good thing street layouts don't have an impact on the housing types that line said streets. Surely we can't find innumberable examples of sfh's located on a grid or townhomes in a cul-de-sac. Certainly when I lived in a townhome cul-de-sac I was merely kidding myself.

Another thing is parking, cul-de-sacs make it harder to park, which I understand is a boon to many residents but sometimes I like to visit people who live in those neighborhoods and between the curb cuts and the and yellow fire lanes it was nigh impossible to even find a spot, and this is a suburban neighborhood so its not really akin to bar goers in adams-morgan or H st. The only reason I was there was to visit people.

by drumz on Jul 31, 2012 1:19 pm • linkreport

"I love the continued war on single family neighborhoods from this blog, especially the posts by those who don't live in the County most of the time, don't own property here and think we have endless pots of money to retrofit everything to fit THEIR vision of what they want"

1. wanting fewer cul de sacs is not the same as being against SFH neighborhoods.

2. While dan blogs about MoCo, this is an issue for many suburbs. I live in Fairfax, and I am glad this issue has been raised.

3. Money is certainly an issue. To the extent this is about retrofitting, its certainly a good idea to look for cheaper options

by AWalkerInTheCity on Jul 31, 2012 1:21 pm • linkreport

Good post.

I would add that this is not limited to Silver Spring. Bethesda, Arlington, and DC have their share of residents who have closed their streets off despite being public right-of-ways that all residents are funding. Whether they are rush-hour turn restrictions, or berms or physical barriers, the only real impact is on neighboring streets. Ultimately, all of the streets will be closed off, causing huge gutters on minor arterials and follow-on environmental (ie air-quality) impacts.

by William on Jul 31, 2012 1:25 pm • linkreport

Glad this came up. I commute from upper NW DC (East of the park) to Bethesda every day. The streets just east of Bethesda all have no entrance from Connecticut to Wisconsin. They have intentionally made the CBD of MoCo extremely difficult to get to. Options going E-W are Military, Western, Bradley, and EW Highway. There are some other options further north, but suffice it to say they are at 100% capacity from people avoiding the Beltway.

The left turn from Wisconsin to EW Highway is a nightmare, takes like 4 light cycles to make it through, basically rendering this option useless. Frustrating that the millionaires who live on these streets get to live walking distance from Bethesda, all while making it extremely difficult to actually get to Bethesda.

by Kyle-w on Jul 31, 2012 1:32 pm • linkreport

Having lived and worked in a very suburban and developing jurisdiction before moving to Silver Spring - I know a lot of the mentality of the cul-de-sac is an assumed sense of safety. People would say they find the one way in, one way out design safer because if their house is robbed, the police can just seal of the entrance and catch he criminal (seriously, i heard someone say that). I even remember bloggers in Baltimore 3 years back saying the city should break up the grid with concrete walls and/or chains, to confuse criminals and therefore the city would be safer.

What I never understood is the people who are often moving to the outer suburbs from the inner ones often say they made the move for safety and schools. Then they live their lives fearful of criminals and send the kids to private school anyway. Why move if you're not going to change your habits at home!

by Gull on Jul 31, 2012 1:43 pm • linkreport

@kct

Are there endless pots of money to retrofit traditional street grids to make more cul-de-sacs? I love how everyone demands fiscal prudence except when it comes to their own wishes.

by watcher on Jul 31, 2012 1:58 pm • linkreport

@kct:

I love the continued war on single family neighborhoods from this blog, especially the posts by those who don't live in the County most of the time, don't own property here and think we have endless pots of money to retrofit everything to fit THEIR vision of what they want.

Could you explain what you're talking about? I really don't follow. Are you saying that suggesting that streets should remain connected in a grid amounts to a "war on single family neighborhoods"?

by Gray on Jul 31, 2012 1:59 pm • linkreport

I live in an area of the city where a particular street was partially blocked off to "eliminate" truck traffic from the neighborhood (there are some warehouses on the one block of the street that is no longer connected to the neighborhood). While the park installed has been effective at limiting the amount of truck traffic we see, there have been some downsides, as well.

First, the overall grid remains intact, so commuters AND trucks that would use the neighborhood as a "cut through" between main arterials can still accomplish their goal. However, instead of doing so by driving down one street in the neighborhood, which is pretty wide and only has houses on one side, they accomplish it by driving right through the heart of the neighborhood, using pretty cramped streets with houses, and therefore lots of parking, on both sides. They have to cross not one intersection in the "heart" of the neighborhood, but 4 going one way and 5 going the other. Those intersections and streets host far more pedestrian and bicycle traffic, and in areas where there's a reason to cross the street, than the previous route. While there are likely fewer cars and trucks willing to take a slightly more circuitous route, there are still plenty willing to do it, and do it dangerously (very fast, not stopping - or even sometimes slowing - at stop signs, cutting off oncoming traffic because the road's really too narrow for 2-way traffic - particularly if one of the vehicles is a box truck). Cutting off that intersection completely would not help, either. Traffic would just take yet another different route...actually, one that would funnel most of the traffic down MY street...and dice the community up into even finer bits for us locals that need to get around.

Second, the sharp turn and weird traffic mingling introduced by this park/blockage is a constant source of danger for drivers and pedestrians. Rather than having a controlled intersection with a stop sign, there's now an uncontrolled (but marked) crosswalk for pedestrians to access the park, a "yield" for traffic to merge with the next intersection, and a barrier in the middle of the street to keep traffic coming around the curve from making lefts at the next intersection. I've seen several drivers take this corner too fast (yes, there are warning signs, so, yes, it's their own fault). This makes the crosswalk to the park dangerous (it's also hard to see until you're part-way around the corner) and has resulted in several major accidents (cars have ended up on the guard rail - would have been the sidewalk without it - in the park, etc.), which results in expensive repairs for both the driver and the city. Drivers also pull illegal U-turns to get back to the "no left" intersection, which mucks up traffic and puts the many children who, for example, ride their bikes in the street in danger.

Finally, this route would be the fastest way to walk or bike to some nearby retail. However, the sparse traffic makes this an inhospitable option, which is where the death spiral starts. It seems dangerous to walk on a lightly-traveled street, particularly after the warehouses have closed, so there's little pedestrian traffic, making it even more dangerous to walk the route. So, because there's little pedestrian traffic, the warehouses have decided they can do whatever they want, including parking on the sidewalks, storing equipment on the sidewalks, not shoveling snow, not treating ice, etc. And down and down the rabbit hole we go, shipping pedestrians further out of their way for a safe walk rather than making the fastest route a reasonable option. In addition, a HUGE chunk of the crime that occurs in our neighborhood occurs on this single block, and another good chunk in the block of the neighborhood preceding it. But of course, the police can only access these blocks from one side and the light usage of these blocks lends itself to further criminal activity away from the eyes of passers-by.

I'd encourage people to think a little more about what might happen if they seal their streets off. People are going to drive through neighborhoods, even if you make it hard for them to do so. Making it hard to do so might just make it more dangerous for everyone. What we really needed to keep the trucks out of the neighborhood was EFFECTIVE ENFORCEMENT OF EXISTING PROHIBITIONS ON THROUGH TRUCKS. We still don't get the enforcement we need, of either the trucks that continue to traverse the neighborhood or the drivers who are now cutting through busy residential blocks, often lawlessly. The money spent on the park could have put in a lot of speed bumps and paid for some additional enforcement. Instead we have pushed the problems right into the middle of the neighborhood, made walking and biking less safe and convenient, and opened an opportunity for criminal activity to flourish. This move was a complete failure.

by Ms. D on Jul 31, 2012 2:26 pm • linkreport

The issue is less about cutting through residential streets in this congested county and more about driving behavior. I live on an approach to the FDA and drivers routinely speed down my 25 mph street at 40 or 50, flying over the speed bumps that residents spent years begging to have put in. Even if we discount all the fauna and domestic animals in our community, what does everyone think about the risk to our children, at least one of whom is a challenged toddler? I am absolutely sympathetic to homeowners who want these crazy drivers off our residential streets.

by Kim on Jul 31, 2012 2:51 pm • linkreport

anyone flying over speed bumps is doing damage to their vehicle. Do people really routinely do that? There are also other forms of traffic calming (like those mini traffic circles) that allow slow speed (and bike/ped) connectivity but are difficult to speed through

by AWalkerInTheCity on Jul 31, 2012 2:55 pm • linkreport

Friendship Heights has a few blocks that have been turned into virtual culs-de-sac. Unfortunate stuff.

I remember this being an issue in State College, PA, as well.

by Geoffrey Hatchard on Jul 31, 2012 2:56 pm • linkreport

I agree with Kim about the speed of these drivers even though I'd like them to keep these streets open to the public, both from an urban and patriotic perspective. So how to accomplish both? Build taller speed bumps. There are some that feel like road kill but there are some that will kill your suspension. Compare the ones in the town of Chevy Chase vs. East Silver Spring, and then guess which are the upgraded ones. Also, allowing for parking on both sides of a narrow street forces drivers to que up when facing eachother and there's only one lane to get through. Win, win, becasue if those streets are 25mph, these traffic calming devices and others will do the trick.

Also, build sidewalks everywhere in a halfmile of any metro station or bus stop. Many of the same people who want to turn their communities into gated enclaves will claim ownership of right-of-ways that the county never got around to building the sidewalk on.

Your property is yours, while the public's is the public's. If we start delineating areas where some have more rights than others will only lead to problems, besides not being fair.

by Thayer-D on Jul 31, 2012 3:01 pm • linkreport

While it's likely too expensive to retrofit cul de sacs, a cheaper improvement with a better return is creating ped/bike paths that connect cul de sacs to other neighborhoods. While I sympathize with the difficulty of driving through an area with cul de sacs, the bigger impact from that design is on walking.

by Falls Church on Jul 31, 2012 3:07 pm • linkreport

@Gray

Could you explain what you're talking about? I really don't follow. Are you saying that suggesting that streets should remain connected in a grid amounts to a "war on single family neighborhoods"?

Well, the very next GGW post is about legalizing two-family houses in MoCo, so clearly GGW is, in fact, declaring a war on single family neighborhoods and residences. QED.

by Dizzy on Jul 31, 2012 3:09 pm • linkreport

Those who watched Gilmore Girls would know that the plural of cul de sac is culs de sac.

by movement on Jul 31, 2012 3:21 pm • linkreport

Great article, Dan. Couldn't agree more. Ellsworth Dr is the perfect example of a street that should (and could) have much wider, fully connected sidewalks and bike paths leading into downtown Silver Spring. Throw in some speed humps and chicanes and we would have a street that is more inviting for pedestrians and still allows cars to travel through. Seattle's SEA streets program is a great example: http://www2.cityofseattle.net/util/tours/seastreet/slide1.htm

by Mark Noll on Jul 31, 2012 3:36 pm • linkreport

I think it is fine. I live in this type of set up and I like how the traffic stays away from my house. It keeps the area quiet and not noisy. Better quality of life for me. I don't know what to say about the commuters.

by Thoms Hen on Jul 31, 2012 3:50 pm • linkreport

@ Dizzy:the very next GGW post is about legalizing two-family houses in MoCo, so clearly GGW is, in fact, declaring a war on single family neighborhoods and residences. QED.

Two short blogs on the internet constitute a "declaration of war"? Wow, that word is suffering from inflation. Here I am thinking wars have to do with armies and bombs and stuff.

by Jasper on Jul 31, 2012 3:55 pm • linkreport

@Thomas Hen,

Well, except that the people who use the road aren't necessarily commuting. And if you live in the neighborhood you may have to backtrack to get onto the arterial which makes for more traffic for everyone.

And commuters are generally cutting through what residential streets they can because the main arterials are so backed up, if the traffic is dispersed over a wide network then the pressure is relieved as a whole, which can make your personal trips around the neighborhood (such as to the store) less of a headache.

Besides, its not commuters, its speeders/reckless drivers that you have a problem with. I don't think cramming everyone onto one road so that traffic is backed up is the best traffic calming strategy.

by drumz on Jul 31, 2012 4:00 pm • linkreport

In my particular situation, my office is downtown, but nearly all of my work takes place in the suburbs at client offices (mostly). In the interest of fairness, I think I should only have to pay the commuter tax on those days that I actually work and earn revenue in DC, which is only about 10% of my salary. The rest comes from the surrounding suburbs, NY, PA, CO, and Europe.

by Ivan McCalister on Jul 31, 2012 4:13 pm • linkreport

@Jasper

Two short blogs on the internet constitute a "declaration of war"? Wow, that word is suffering from inflation. Here I am thinking wars have to do with armies and bombs and stuff.

You're just learning this now? We're three decades into the War on Drugs, possibly in an on-again phase of the War on Poverty, and full speed ahead in the War on Christmas!

I assume you understood I was being sarcastic.

by Dizzy on Jul 31, 2012 4:16 pm • linkreport

@ Dizzy: Sorry, I should have quoted kct, who started the "metaphor". I am soooo tired of everything being a war, while the real wars are now generally peace-enforcement operations. In that light, it is appropriate that the War of Drugs is fought by the Drug Enforcement folksies.

by Jasper on Jul 31, 2012 4:35 pm • linkreport

There is nothing wrong with culdesacs the issue is one persons preference over another's. Just live and let be if you do or dont like it so what; it does not effect you unless you have to travel there.

They are no different than dead end streets, one way streets that are followed by one way streets, highways blocking access to streets or other barriers. The only difference is that the cul-de-sacs were built that way on purpose.

If you dont like it again do live near or go near them dont try to force your opinion on others who may like them.

by kk on Jul 31, 2012 5:15 pm • linkreport

There is nothing wrong with culdesacs the issue is one persons preference over another's. Just live and let be if you do or dont like it so what; it does not effect you unless you have to travel there.

Amen to that! I even thought of the one-way street comparison myself. DC is full of them.

by HogWash on Jul 31, 2012 5:16 pm • linkreport

Just live and let be if you do or dont like it so what; it does not effect you unless you have to travel there.

That's the whole point - because of culs-de-sac there's no street grid so all kinds of traffic gets funneled onto arterials when it doesn't necessarily need to be, messing up traffic further.

It is different than a one-way street (when DC has them there is almost always one going the opposite direction a block over) or a dead-end street that dead-ends NECESSARILY (because of railway or highway, etc.) Culs-de-sac just dead-end for no reason and make people travel further than necessary to get places.

by MLD on Jul 31, 2012 5:48 pm • linkreport

Kolohe: giving citizens or private contractors the power to run speed cameras is not the same as giving them the power to shoot and kill people. Private contractors run speed cameras all the time in Australia, and send out tickets for a cut of the proceeds.

by SJE on Jul 31, 2012 7:47 pm • linkreport

@MLD

I'm not specifically speaking of DC; I have seen two one way streets going in the same direction back to back, two one way streets intersecting each other and so one.

There are some streets that dead end for no reason, there are some streets tht are one block long in the area but nothing is blocking them from being longer.

If a developer, or owner etc wants to make cul-da-sacs so be it. How is this any different than a person having to taking main roads inside of DC to get around. Georgia Ave/7th Street, 16th Street, New York Ave, South Capitol and Connecticut Ave are some of the only ways to get in and out of some areas of DC

What about all of the windy roads in rural parts of Maryland or Virginia they have they are the same.

Most of the street grids in the area are not so great either. DC is a perfect example many curved windy roads that do not take the easiest or quickest route from start to finish when there is or was nothing impeding them at the time of first construction of the road

by kk on Jul 31, 2012 8:32 pm • linkreport

You can prefer culs-de-sac, just realize that there are trade offs. Increased vmt and travel times being one of them. It is a personal preference but it's one that has a profound impact on everybody.

by Drumz on Jul 31, 2012 10:34 pm • linkreport

[Deleted for violating the comment policy.]

If you want more density in commercial areas, then there has to be traffic calming in quiet, adjacent residential streets. Bethesda and Arlington County have figured this out -- DDOT, not so much. The biggest drivers (no pun intended) of opposition to nearby development are concerns about traffic and parking. If you figure out a way to mitigate those concerns somewhat, as the above juridctions have done, then it makes the approval process for appropriate development go more smoothly. The idea of flushing traffic through some street grid may make sense in midtown Manhattan, but not in most places where there is a functional hierchy of streets. Traffic calming, including sometimes diverters and turning restrictions, ensures that the road network is used appropriately with its functional classifications.

by Ralph on Aug 1, 2012 10:04 am • linkreport

Ralph,

But those traffic calming measures exist independent of whether the street is connected or not. Its possible to do both. And Manhattan isn't the only city with a grid, the first example I read of the value of a grid actually used Old town alexandria. There the bulk of commercial business is along King Street and Washington but the grid helps act as a pressure valve and traffic is still relatively calm along the residential streets.

by drumz on Aug 1, 2012 10:13 am • linkreport

I think the column is against cul de sacing, not traffic calming.

It makes perfect sense to me that the fastest traffic, the longer haul traffic, etc go on arterials. but cul de sacing forces even slow traffic, even traffic going from one subdivision to an adjacent one, on to the arterial. Unless there is a bike/ped cut through its very bad for biking/ped connectivity, and even where there is a cut through, its often less desirable (crime, maintenance) than a road with a ped facility.

grids work fine in places other than midtown manhattan - in most of DC, in Old town alex, and even in many older SFH areas in arlington and Alex.

Go ahead and traffic calm, by all means. There are lots of ways to do that - speed bumps (but please make them low enough to bike over), traffic circles, narrower streets and on street parking (the neotrad way), two way streets in place of one way, etc. A full on blocking of the road is about the worst way.

by AWalkerInTheCity on Aug 1, 2012 10:20 am • linkreport

"the first example I read of the value of a grid actually used Old town alexandria."

Even in Old Town, streets that should be part of the interconnected grid are blocked off. I live in the quadrant south of Duke and west of Route 1.

It should be relatively easy for me to get into my neighborhood, except that just north of me is a Condo Complex that decided it wanted to block off all traffic on it's streets except to it's residents.

So, to get to my house I'm forced to sit in the daily nightmare that is Duke St. and Route 1 - even though my house is less than a quarter of a mile away at that point. This adds, at a minimum, 5 minutes to my trip, which regularly (every week and a half or so) increases to 15 minutes, and has maxed out at around 45 minutes.

The point being, even when people can see the benefits of a good grid system at work, certain elitists still want their own little private subdivisions.

by Lisse on Aug 1, 2012 1:53 pm • linkreport

This is certainly an interesting planning issue, but I think there are both pros and cons of blocking traffic on some streets (provided pedestrians and bicyclists are allowed through).

In areas with travel options (like downtown Silver Spring), restricting total vehicle capacity is likely to cut down on vehicle use, both by requiring longer vehicle trips and increasing congestion on other streets. This is especially true where measures are taken to encourage walking and biking on the streets without traffic, and as mentioned in the post, that's the strategy behind Berkeley's famous bicycle boulevards. The nearly traffic-free boulevards help make Berkeley's connected grid a great place to walk and bike, but a lousy place to drive because the barriers result in circuitous routes, congestion, and driver confusion.

Also, as Ralph notes, for better or worse densifying the suburbs is often requires cutting a deal with surrounding single family neighborhoods in which residents don't fight development as long as they're promised it will have minimal impact on their suburban neighborhoods. Restricting, reducing, and calming traffic is often part of that bargain and can thereby help gain political support for development.

On the other hand, there are often negative consequences for transit because it usually runs on the arterials that become more congested when other streets are blocked. Having protections in place, like bus lanes, is important to solve this problem, but they aren't usually implemented together with the street blockades.

And finally, there are some serious equity issues with allowing residents of less-trafficked streets and who have enough political power (and are therefore likely to be higher-income) push all the traffic to the arterials, where lower-income people are likely to reside. And these TOD-adjacent residents then get to enjoy all of the property value boost that being next to a dense, walkable, transit-rich area provides without any of the impacts. That's a pretty good deal!

So where do I stand overall? Probably in favor of a larger-scale plan that includes some blockades to create bike boulevards, traffic calming district-wide, and protected transit infrastructure. Admittedly, that's a lot to ask.

by RichardatCourthouse on Aug 1, 2012 2:28 pm • linkreport

@Dan Reed, thank you for the "striping a 'pedestrian lane'" link from Montgomery County, which explains (I think) the new double white line on the right lanes of four-lane Richter Farm Road in Germantown -- something I had been wondering about.

by Miriam on Aug 1, 2012 3:19 pm • linkreport

The photo of the Berkeley bike boulevard is a great example of smart traffic calming near a busy arterial where "destination" retail is likely to be. Cut through vehicular traffic is discouraged on a residential side street, but bicycle and pedestrian traffic is encouraged. There are some other nice examples of this in Balston and Bethesda. And, in fact, such traffic calmed streets are not cul-de-sacs -- they are usually part of a grid or connected to multiple other streets. It's just that they are protected from becoming feeder streets to large retail destinations like in Friendship Heights or along Clarendon Blvd. These can become regional traffic generators and without mitigation measures, can fundamentally (and sometimes negatively) alter the safety, environment and quality of life in adjoining neighborhoods.

As for arterials becoming more crowded with through or destination traffic, traffic planners would say that's where it should go. Anyway, isn't it the case with smart growth on the main corridors that patrons are mostsly going to use mass transit anyway? Or not?

by Ralph on Aug 2, 2012 11:04 am • linkreport

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