Traffic Calming in Greenville SC

By Dom Nozzi

Regarding speed humps…

I am possibly the biggest advocate in South Carolina for using traffic calming devices on streets, as I believe slowing cars is one of the most important things we can do in cities for better safety, quality of life, reduction in low-value motor vehicle trips, and noise reduction.

Speed humps, however, are an exceptionally problematic tool for slowing cars. On the list of bad ideas for slowing cars, speed limit signs are at top of the list for being the worst. Stop signs are about as bad. And humps are #3 for being a bad tool.

Here is why humps are a bad idea:

They punish motorists even if the motorist is driving fairly slowly.

They can damage vehicles.

They create noise pollution for neighborhoods.

They create problems for emergency response vehicles.

They are annoying for cyclists.

When spaced improperly, they promote “jackrabbit” driving (ie, frequent slowing and speeding between humps).

An important reason why many cities such as Greenville use (or overuse) humps so often (there are way too many humps in Greenville) is that they are very quick and low-cost to install. Which makes them an easy way for elected officials to satisfy neighbors concerned about speeding vehicles.

However, the best way, by far, to slow motor vehicles is not to use “vertical” interventions such as humps, but to use “horizontal” interventions. Examples of horizontal interventions include:

1.       Road diets, where excessive street lanes are removed. The most common diet is going from 4 lanes to 3.

2.       Landscaped or hard-surface bulb-outs (usually used to frame on-street parking or create a mid-block pedestrian crossing). Many bulb-outs are admirably used on Greenville’s Main Street. Ideally, this “pinching down” the width of the street creates a one-lane-wide pinch point that obligates motorists to “give-way” when a motor vehicle approaches in the opposing direction.

3.       Chicanes, which are a form of bulb-out that obligates motorists to move in a slower, weaving, more attentive pattern.

4.       Traffic circles and roundabouts.

5.       Installing on-street parking on streets without such parking. Again, this narrowing of street width works best when a “give-way” street is created.

6.       Installing formally-aligned street trees abutting the street to create a sense of enclosure and human scale.

Each of these horizontal interventions is much more conducive to bicycling and emergency response vehicles than vertical interventions such as humps. They are also much better at creating a safe environment for walking. As well as created the much-needed human scale and sense of place that is lost when we oversize streets and intersections.

On my list of top priorities for Greenville to become a better city, traffic calming is near the top of the list. But calming needs, again, to be achieved with horizontal rather than vertical interventions.

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Permanently Pedestrianize Pearl?

By Dom Nozzi

The Boulder Colorado City Council recently considered permanently closing Pearl Street west of the Mall.

One response to the pandemic on Pearl Street has been to allow retailers to expand into public streets and sidewalks. In the case of Pearl Street west of the Mall, this has included closing the street to cars.

While I largely support these reforms, I would urge caution. Yes, the idea of reallocating space on Pearl Street to move away from exclusive car use is long overdue and would achieve important benefits. But there are a few likely negative outcomes.

A lot of us “put people before cars” folks will see the idea of closing Pearl to cars  beyond Pearl St Mall as irresistibly seductive.

I’m not so sure.

Urban designers know that prohibiting cars on more than a few blocks is almost always fatal to retail UNLESS there is sufficiently compact mixed-use development along the street. Pearl is far less compact than is needed to support more closure.

Another worry: one suggestion is to reallocate space from cars is to make Pearl a one-way street. One-way conversion was popular in the 60s and 70s, but we now know they are terrible for a town center – particularly for retail. A growing number of one-ways are therefore being converted back to two-way.

Even with a pandemic crisis, it is politically difficult to close streets to cars.

Fortunately, there is a Third Way.

A compromise that would offer enormous benefits, be relatively feasible politically, promote retail health, retain fire truck access, and enhance public health (from both added social distancing space and boosting the amount of walking and bicycling) is a “woonerf.”

I believe the woonerf is a “Third Way” design. It creates a low-speed street design on Pearl – a “living street” safely shared by cars, pedestrians and cyclists (Google “woonerf,” or go to Woonerfs can be installed quickly, relatively cheaply, and temporarily if they do not work out.

Some people call such design “give-way” streets, where the two-way street is so narrow that the motorist must “give-way” to an on-coming car.

Low-speed design would allow two-way car travel to continue on Pearl, but would obligate motorists to drive very slowly (say, 10-15 mph) and very attentively. So much so that even children and seniors would be safe and happy to sit in the street or walk or bicycle in the street.

I recommend the woonerf treatment for Pearl west of the Mall to 9th Street and east of the Mall to, say, 19th Street.

How is a low-speed two-way street created? On Pearl, it would mean removal of the awful design decision of a continuous left-turn (suicide) lane in the middle of the street. That alone allows ample space reallocation.

Second, shrink the width of the travel lanes to, say, 9 feet each. Also shrink the height of signs and street lights to create a “low-speed ambiance.” Add street furniture, and plenty of new green tree, shrub and flower landscaping in elevated “planter” boxes to the street (exactly the way it was done on Pearl St Mall, by the way).

Woonerfs typically eliminate curbs and elevated sidewalks to signal that the street is slow-speed and shared between cars, cyclists, and walkers. By doing each of these things, we would create an extremely safe, happy, vibrant Pearl Street that prioritizes people (cyclists, peds, seniors, children) over cars without eliminating cars.

Cars, as is the case in Dutch woonerfs, are able to remain but they are obligated by the street design to be very slow speed and safely attentive. Retail and restaurant businesses would flourish with the big increase in space, and the much slower speeds by motorists (who, because they are driving more slowly, are more likely to stop and be customers).

The new street design would lead to a jump in the number of pedestrians and cyclists on Pearl Street who were previously too worried to walk or bike there due to the pro-car design. By allowing slow-speed cars, a woonerf allows a city with insufficient compactness to deliver sufficient customers to businesses along the street.


So yes! Let’s reallocate space on Pearl so that it is pro-people rather than pro-car. But let’s do it right, and avoid the mistakes of the past.

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We Have Reached the Point of No Return on Car Dependency

By Dom Nozzi

We have reached the point of no return on car dependency. There is no turning back, despite the persistent, passionate, hopeful efforts of myself and many other advocates for much-needed transportation reform.

Car infrastructure so thoroughly excludes other forms of travel (known by economists as “the barrier effect”) that it has become a powerful form of a self-perpetuating downward spiral.

Nearly all of us are obligated to make nearly all of our trips by car, which obligates us to demand our elected officials ease car travel. The more we ease car travel, the harder it is to travel in other ways, which, over the past century, has continuously increased the proportion of us who must drive everywhere. Any move away from extreme car dependence is understandably seen as a direct, existential threat to our way of life.

Since a car-dependent world destroys our quality of life, we are trapped in a tragic scenario in which we must always push our elected officials to hasten the degradation of our world in favor of convenience for our cars. We have, in effect, become our own worst enemies.

I’m convinced that the only way out of this trap is for there to be a catastrophic economic collapse on the level of The Great Depression.

I’m not sure which is worse: Continued extreme car dependence, or extreme economic misery.

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Is “Twenty Is Plenty” A Good Idea for Greenville, South Carolina?

By Dom Nozzi

Greenville, South Carolina – where I now live – had some of its bicycling and walking advocates consider adopting a “Twenty (mph) Is Plenty” program to enhance walking and cycling safety.

I was asked what I thought of the idea.

I responded by saying that when I served on the Boulder Colorado Transportation Advisory Board, one of the agenda items that came before us was a “20 Is Plenty” campaign, which was ultimately approved by Council.

I expressed serious reservations at the time.

While it is extremely important to effectively slow motor vehicle speeds, revising speed limit signs down to 20 mph does almost nothing to meaningfully slow vehicle speeds because what controls vehicle speeds is almost entirely based on the design speed of streets. Almost no motorist pays any attention to signs. Lowering limits on signs, therefore, can be seen as little more than ineffective lip service.

Cities like Boulder and Greenville have an enormous number of streets with design speeds far above 20 mph, which powerfully induces excessive speeds by vehicles.

An important concern here is that a great many might conclude that “our work is done” on slowing vehicles, simply because we’ve lowered limits on signs. Such people don’t realize that work has not even started if we simply change speed limit signs.

Another moderately legitimate argument against lowering limits on signs without lowering street design speeds is that this is an underhanded way to allow the City to collect revenue, as the lower limits on signs will — due to higher design speeds for streets — lead to a jump in speeding tickets.

A counterargument to my “lip service” concerns is that our community — by lowering limits on signs — has sent a message to city government and the South Carolina Department of Transportation (SCDOT) that our community strongly desires slower vehicle speeds. And we want the City and SCDOT to start getting serious about designing streets for slower speeds.

Effective tools?

Much more on-street parking. On-street parking provides a quick and low-cost calming tool for our community. Such parking provides a safety and convenience boost for homes, a way to reduce noise pollution, a way to reduce the need for large asphalt off-street parking lots, and a way to provide a financial boost for small retailers. Ideally, on-street parking creates a “give-way” street, which is a street that is narrow enough that motor vehicles approaching each other from opposite directions must have one of the vehicles give way to allow them to pass each other.

Road and intersection diets (ie, removal of excessive travel and turn lanes).

Landscaped bulb-outs (to reduce the width and crossing distance of streets).

“Woonerfs” (Dutch “living street” design — see Wall St in downtown Asheville NC).

Converting one-way streets back to two-way operation.

Replacing stop signs and traffic signals with traffic circles and roundabouts.

Installing large canopy street trees.

Replacing the several miles of dangerous “continuous left turn lanes” throughout Greenville’s town center with raised medians.

Reducing the height of street lights, signs, and traffic signals.

By the way, I believe it is important that we actively oppose the use of speed humps for vehicle speed reduction (an all-too-common calming method that has important downsides). This City needs to remove existing humps, as they are a noise pollution problem, punish even slower speed vehicles, are terrible for cyclists, and are a serious problem for emergency vehicle response. Removing the humps needs to be coupled — simultaneously — with installation of preferable tools such as methods I mention above.

It must also be noted that humps give traffic calming efforts a black eye, as a great many citizens are understandably highly annoyed by humps, and that annoyance is often generalized to apply to all forms of calming.

In sum, I’m happy to see the widespread interest in slower speeds for vehicles. I don’t necessarily oppose a “20 Is Plenty” effort to reduce limits on signs. But we need to be careful about strategies to effectively achieve that exceptionally important objective of slowing vehicles, and not just pay lip service to our doing that.

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About the Author

Dom Nozzi has a Bachelor’s in environmental science from SUNY Plattsburgh and a Master’s in town planning from Florida State University. For 20 years, he was a senior planner for Gainesville FL, and a planner for Boulder CO. He has spent 40 years working academically and professionally in town planning, urban design, and transportation – particularly designing for walking, bicycling, and transit.

He has delivered over 100 speeches across the US. He is a prolific blogger.

He was a Neighborhood Assoc. president in Gainesville. He served on a Condo Assoc. Board of Directors in Boulder. He was the founder and chair of the Mapleton Hill PorchFest in Boulder.

He was a member of the Congress for the New Urbanism. He authored several environmental, transportation and urban design plans and regulations for Gainesville. He is in Who’s Who for the South and Southwest. 

He has served on the Board of Directors for Bike/Walk Virginia. He has served as a Complete Streets Instructor in several cities throughout the nation. He was an adjunct professor for the University of Colorado and served on the Boulder Transportation Advisory Board. He served on the PLAN-Boulder County Board of Directors. He currently serves on the Bike/Walk Greenville SC Board of Directors.

He has written and published several books. A list of those books can be found here.

He is a lifelong bicycle commuter. He is a world traveler, skier, hiker, kayaker, single-track mountain bicyclist, skydiver, and scuba diver. He has toured over 56 Italian cities and visited 26 nations.

He has hiked 154 named trails in the Colorado Rockies, totaling 1,810 miles.

He is an accomplished cook, and a satisfying dancer.

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Will the Flight from the City Due to COVID Persist?

By Dom Nozzi

A number of folks have stated that our society will see a permanent and significant increase in people working remotely from their office (i.e., telecommuting) as a result of COVID.

But I’m not convinced.

I don’t believe we will see a permanent and significant shift toward remote living and work or telecommuting. Nor do I believe we will see a reversal in the trend of large numbers moving into a town center home.

For two primary reasons.

First, we know employees and other humans are more productive and more prone to brilliant insights (through the synergy effect) when they engage in close interaction with others. This is true both when humans are in the same building or room, and when the density of a city is higher. There is a very strong correlation between city density and patents, inventions, innovations, high IQ, etc.

Second, humans are a social species. Most of us are hard-wired to be happier and more thriving when we interact with other humans rather than being isolated.

I imagine, however, that it could be true that introverts might do better as employees if they live/work remotely. But even if that is true, I think such people would be a minority. One estimate on the internet says introverts are about 25% to 40% of the population.

I asked a friend who is convinced we will see a long-term increase in remote work if she would prefer engaging in coffee meetups where instead of our meeting at a café, we all stayed home and engaged in coffee chats through our computers and phones (“Zoom/Skype meetings”)?

I strongly suspect not.

I watched a video yesterday where a guy who lived in several countries in the world pointed out that by far, Americans are the most fearful population he experienced. I think that COVID and the 24/7 campaign of our media making us scared out of our wits are fueling the flight from town centers and work at the office, but again, I’m confident this is short-term.

Speaking as a town and transportation planner, I’d say another repellent for American town centers is that nearly all of them are so overly designed for happy cars (massive highway overpasses, massive parking lots, massive parking garages, massive and blank-walled buildings, massive building setbacks, massive amounts of motor vehicle noise and fumes, massively tall highway lighting on streets, massive billboards, massive intersections and highways/roads) that their quality of life for humans is shamefully appalling.

Even though I love the idea of living in a walkable and very dense setting, I have very little interest in living in the downtown of a big American city for the reasons I mention above. I’m convinced that various factors will see downtowns incrementally transform themselves into being places that have a higher quality of life and more human scale in the coming decades. That will be another reason why there will be a return to town centers when COVID is in our rear view mirror.

One last thing: the main reason cities have existed for so much of human history is to promote exchange. Exchange of ideas, goods, and services. Today’s technologies make that more possible remotely, but it will never lead us to a world where humans mostly live and work remotely from each other and cities go away.

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What Do I Think of the High Ratings for Vancouver?

By Dom Nozzi

Someone read one of my blogs about my ratings for the best cities in the world. He then asked me the following: “How would you rate Vancouver? Would it potentially make it on your best-ever list in the future? And what do you think is the reason why it seems to get so much amazing press? From a cursory Google Images search, the downtown looks to me like a whole lot of nondescript glass towers.”

My reply: I’ve long been intrigued by Vancouver, as the city is often ranked quite high as a quality city, which led me to be eager to visit to see for myself.

When I visited, I was disappointed.

As you say, the city has a lot of rather tall, intimidating glass and modernist towers. I did not find much at all in the way of charming walkability or human scale.

It was easy to see that as noted by reports, the city has quite a bit of town center housing, which surely must be good news for town center retailers (and, perhaps, a good amount of town center walking).

But what Vancouver illustrates to me is, in my experience, almost an iron law of cities or neighborhoods: The older the city or neighborhood, the more human-scaled and charming and walkable and romantic it is. The newer the city or neighborhood, the less one finds those elements.

This illustrates that our generation is failing to leave a quality legacy for future generations (in terms of the places we build). I believe this is largely due to two things that emerged in the 20th Century: the Modernist design paradigm for buildings, and our car-dependent society. Because cars consume so much space, it has become nearly impossible to create human-scaled, charming places anymore, as cars don’t allow us to do that. Design for motor vehicles is utterly incompatible with design for charm.

It is a tragic dilemma.

Does Vancouver have the ability to make my best-ever list of cities in the future? I believe that because we have built so many modernist, car-happy (i.e., unlovable and unwalkable) places, most all cities in North America will at some point have a future where such places become so unaffordable to maintain and so disliked that we will set about engaging in a lot of demolition and (hopefully) rebuilding such places to be human-scaled and charmingly traditional.

I fear that such a day is a long way off, however. A great deal of economic misery will be required to motivate us in that transformation and restoration.

In sum, I don’t expect Vancouver to make my best-ever city list in my lifetime.

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Effective Safety, Economic Enhancement, and Protection for Homes on Stone Avenue in Greenville

By Dom Nozzi

Is the City of Greenville South Carolina serious about improved safety on Stone Avenue?

The question must be raised as the City has recently initiated an effort to improve safety on this road — a road that is notoriously dangerous.

The City will show it is not serious if it opts for what all cities have tried for the past century to “improve” traffic safety. For the past century, cities have opted for the same ineffective tactics that have suffered from extreme diminishing returns for several decades.

I call them the “Five Warnings”: More Warning Lights, More Warning Paint, More Warning Signs, More Warning Education, and More Warning Enforcement.

Stone Ave will remain a car-only death trap — particularly for seniors, children, bicyclists, pedestrians, and the handicapped — unless the City assumes ownership of Stone from the South Carolina Department of Transportation (SCDOT) and installs a road diet.

Going from 4 or 5 lanes to 3 lanes is a no-brainer. Dover-Kohl consultants had previously called for a road diet, and SCDOT rejected it.

A road diet will quickly and cost-effectively result in

(1) significant improvements for homes along and near Stone (which will increase property values and therefore tax revenue to local government);

(2) significant improvements for smaller retail shops along Stone (which will increase sales tax revenue to government);

(3) significant improvements for cycling and walking along and across Stone (resulting in an increase in the number of bicycling and walking trips on Stone);

(4) significant improvements for children and seniors and the disabled using Stone; (5) a significant drop in crashes on Stone (reducing injuries and deaths);

(6) a reduction in speeding and average motor vehicle speeds on Stone;

(7) a drop in dangerous lane-changing by motor vehicles;

(8) motorists, bicyclists, walkers, the handicapped, and transit users will feel less stress (and more happy civic pride), and notice more homes and businesses along this section;

(9) bicyclists and walkers will more often encounter friends (and make new friends) along this section;

(10) a reduction in road rage;

(11) an improvement in aesthetics of this section;

(12) a reduction in noise pollution along Stone; and

(13) a big drop in City maintenance costs (read: lower taxes).

By the way, a Stone Avenue road diet will perform more successfully if it includes the following:

(1) a reduction in the height of signs, street lights, and signal lights (post-mounted signals are ideal for this) along the street. Creating this more human-scaled dimensioning would make the street look better and further slow down cars;

(2) a reduction in the turning radius at driveway and street intersections. This would reduce crossing distance for walkers (to improve safety and convenience); reduce turning speeds by motorists, and increase motorist attentiveness;

(3) a modest width for the center turning lane. Conventional engineers are notorious for creating excessive turn lane widths, and they have done it again on this section. Note: Engineers will claim the excessive width is necessary. Nonsense. It is a motorist convenience measure. Motorists SHOULD be somewhat inconvenienced in this town center location. Excessive width increases motorist speeding and inattentiveness, and reduces safety for crossing walkers and handicapped. As an aside, through lanes in this section might also benefit from being narrowed (I do not know their width);

(4) To dramatically improve safety and aesthetics, the Stone Avenue road diet should avoid a continuous left-turn configuration and instead use left-turn pockets interspersed with raised and either landscaped or brick (the lower-maintenance option) medians.

A road-dieted Stone Avenue should not have any instances where the road exceeds three lanes (i.e., more than one turn lane is present). No roads in the town center should exceed three lanes for a large number of reasons. I have noticed that there are, for example, an excessive number of lanes on North Main Street north of Elford Street.

Not making the above corrections means that we reduce the visible success of the road diet. That, of course, is a tactical mistake. We need to maximize the benefits of road diets to increase the political will to achieve the many more road diets we desperately need on several oversized roads in the town center.

Important note: Going from 4 lanes to 3 does not reduce road capacity, nor will it significantly increase travel times on Stone, despite the conventional wisdom.

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Requesting Safe Speeds for Croft Street in Greenville SC

By Dom Nozzi

We need to have the City of Greenville deliver a “Neighborhood Slow Zone” sign to our Greenville home in our north Main Street neighborhood due to excessive car speeds.

While such signs will do little, if anything, to slow cars on our street, it does perhaps send a visible message to neighbors and others in the city that we need slower speed street design.

For the record, when the City is in a position to engage in the much-needed re-design of Croft Street from Rutherford Street to Wilton Street to obligate motorists to drive at slower, more attentive speeds (i.e., speeds that are compatible with safety for children, seniors, the handicapped, and bicyclists), that design must include horizontal interventions, not vertical interventions.

Desirable horizontal interventions include:

*Landscaped bulb-outs forming pockets for on-street parking

*Painted on-street striping for on-street parking


*Abundant planting of large canopy trees abutting the street curb

*Human-scaled (rather than excessively tall highway-scaled) black wrought iron and historically designed street lighting that is no taller than 14 feet

*Brick crosswalks/intersections

Undesirable (vertical) interventions include:

*Speed humps – humps are exceptionally undesirable for a number of reasons: They create noise pollution, they can damage cars (even those driving at low speeds), they are extremely undesirable for bicyclists, and they are extremely detrimental to public safety because of their exceptionally negative impact on emergency vehicle response.

Note: Ideally, for safety, reduction in noise pollution, and property values, the section of Croft Street I identify above should be designed to be narrow enough to create “give-way” street dimensions. In other words, dimensions that obligate motorists in opposing directions to give way when a motor vehicle approaches from the opposite direction.

I lived on a give-way street in Gainesville Florida and can therefore understand why traffic engineering studies show that give-way streets are extremely safe, walkable, and considered to be such a desirable street that the most wealthy families in my city ended up living on that street.

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Designing Streets Properly

By Dom Nozzi

My partner posted a short video showing a child on a bicycle being hit by a motorist. A friend noted in response that there were two problems: a speeding motorist and a careless bicyclist.

When streets are properly designed, the INEVITABLE careless, inattentive behavior of adults, motorists, children, animals, bicyclists, walkers, the handicapped, and seniors makes deadly or disabling crashes highly unlikely. As it has stood for the past century, “safety” efforts in street design have made our streets more dangerous than ever, because the design paradigm is single-mindedly focused on “forgiving” motorists for driving too fast and too inattentively.

Only when we reverse this design paradigm so that it obligates slower, more attentive motoring will we move toward achieving reasonably safe, civilizing, pro-city streets.

Shame on us for not replacing conventional traffic engineers with engineers that are pro-city and pro-safety and pro-child. Shame on us for not giving engineers permission to design pro-city and pro-safety and pro-kid streets.

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