Walking and Talking: The Effect of Smartphone Use and Group Conversation on Pedestrian Speed.

Camera Layout, Broadway study site

Recent working paper:

By testing the walking speed of groups of pedestrians and of phone users, followers of groups and of phone users, and of people uninfluenced by phone users and groups, from different sites it could been seen that groups of people and phone users, and often followers of phone users, walk significantly slower than people uninfluenced by phone. In a narrow path people in groups and phone users not only slow themselves down but also slow the people behind. The rise of the smartphone correlates with a reduction in walking speed.

Why Looking at Crash Stats Alone Doesn’t Tell the Whole Story About Pedestrian Safety | Streetsblog

Stephen Miller at Streetsblog writes Why Looking at Crash Stats Alone Doesn’t Tell the Whole Story About Pedestrian Safety: New research from Minneapolis shows that there is safety in numbers for pedestrians.

This map shows the number of crashes involving pedestrians in relation to the number of people who walk at a given location. Via Murphy, Levinson, and Owen

This map shows the number of crashes involving pedestrians in relation to the number of people who walk at a given location. Via Murphy, Levinson, and Owen

Some intersections are riskier to cross than others, but looking at the number of pedestrian injuries alone doesn’t tell the whole story. A new study from Minneapolis combines crash data with pedestrian counts to deliver a more nuanced picture of traffic dangers for people on foot. Among the findings: There’s safety in numbers for pedestrians.

Using data from the city government, University of Minnesota researcher Brendan Murphy and his co-authors looked at 448 intersections where both pedestrian counts and automobile counts were available, then cross-referenced that data with the city’s crash reports. They found a strong negative correlation between the number of pedestrians and the risk of being hit by a car.

While the study found people are less likely to be struck by a driver at locations where lots of people walk, it does not establish causation, Murphy says. “We don’t have good statistical evidence to show that if a place is safe, people will walk — or in the other direction, that if people are walking, they make the place safer,” he says. “I personally think it’s a bit of both.”

Per person, pedestrian-rich areas downtown and near the University of Minnesota pose a low risk for people walking, though they have a high absolute number of pedestrian crashes. Quieter intersections in more residential neighborhoods also pose a lower risk.

A few streets jump off the map as high-risk areas, like Lake Street, which runs east-west across South Minneapolis, and Penn Avenue in North Minneapolis. Both are used by a steady if not enormous number of pedestrians, but are meant first and foremost to move lots of cars. “We can ask, ‘How are those roads designed?’” Murphy says. “They are two lanes each way, no shoulder or bike lane.”

The study looked at all crashes involving pedestrians, not just injuries and fatalities, in order to include enough data points to reach reliable conclusions. It also looked at the stats from 2000 to 2013 in aggregate, rather than year-by-year, so it doesn’t take into account intersection redesigns or major changes like the opening of a light rail line. If there were enough data, Murphy says, “it would be really nice to do a year-by-year analysis.”

The study did not consider the relationship between pedestrian risk and income or race, but the authors say that needs attention. “Equity is a very big problem in terms of pedestrian safety and poor and minority people are getting killed by cars at much higher rates,” Murphy said.

The authors hope their research will lead to better measurements of pedestrian safety and methods to improve it. In 2016, the U.S. Department of Transportation’s four-year strategic plan set a goal of reducing fatalities for pedestrians and cyclists to 0.15 per 100 million vehicle miles traveled by 2016. But that’s the wrong way to look at the problem.

“If we frame pedestrian deaths in terms of VMT, we’re really framing it in terms of automobiles themselves and car traffic,” said Murphy. “We should be focused on reducing pedestrian deaths as a percentage of the pedestrian population.”

There’s also a need for better data collection. Cities and states regularly collect standardized data on car and truck traffic, but there’s no standard for non-motorized users. This data is often collected manually and its reliability varies from city to city. In Minneapolis, three counts throughout the day at each intersection were added together to create a six-hour total. Other cities have different methods.

“Ideally we would like to have our cities wired up and know how many pedestrians are crossing each intersection,” Murphy says. “We need to focus in on the pedestrian population and really ask ourselves, where are they really experiencing undue burdens of risk and what can we do about it?”

Evaluating the Safety In Numbers effect for pedestrians at urban intersections

Recently published:

Average annual 6-hour pedestrian count by location, Minneapolis
Average annual 6-hour pedestrian count by location, Minneapolis


  • Collision risk at 448 intersections in the city of Minneapolis, MN was assessed.
  • The Safety In Numbers phenomenon was observed for both pedestrians and cars.
  • Maps of per-pedestrian crash rates inform discussion of safe vs. unsafe city areas.


Assessment of collision risk between pedestrians and automobiles offers a powerful and informative tool in urban planning applications, and can be leveraged to inform proper placement of improvements and treatment projects to improve pedestrian safety. Such assessment can be performed using existing datasets of crashes, pedestrian counts, and automobile traffic flows to identify intersections or corridors characterized by elevated collision risks to pedestrians. The Safety In Numbers phenomenon, which refers to the observable effect that pedestrian safety is positively correlated with increased pedestrian traffic in a given area (i.e. that the individual per-pedestrian risk of a collision decreases with additional pedestrians), is a readily observed phenomenon that has been studied previously, though its directional causality is not yet known. A sample of 488 intersections in Minneapolis were analyzed, and statistically-significant log-linear relationships between pedestrian traffic flows and the per-pedestrian crash risk were found, indicating the Safety In Numbers effect. Potential planning applications of this analysis framework towards improving pedestrian safety in urban environments are discussed.


  • Pedestrians;
  • Safety;
  • Collisions;
  • Urban planning

The Elements of Vibe

What is vibe? Vibe is the vitality of street life, the feeling that there is something going on, of being where the action is. Successful places have vibe, dead places don’t. We don’t want vibe everywhere and probably can’t support it. But surely we could have more active places then we do now with a better location of activities.
We drive to places we can walk around, rather than walk around our own neighborhood, unless we happen to live in a place with vibe.
Why do we want to walk around? Because there are multiple things to do: find food, browse books, hear music, entice the intellect, stimulate the senses. This concentration of activities only happens because of the crowds around, and the crowds only gather because of the concentration. More begets more.
These are ‘economies of agglomeration’ as the economists might say or perhaps ‘network effects’. But they allow for the spontaneous walk-in business rather than the planned trip. Many businesses are unlikely to attract spontaneous walk-ins, for instance vacuum cleaner repairs, [I don’t normally walk around with a vacuum cleaner on the hope I will find a repair shop] and thus lose little by not being located in the center of action and save much on rent. Some restaurants are so good, they require a reservation, and thus there is little spill-in traffic. But other businesses, by saving on rent, are foregoing additional business.
Moreover, those businesses are denying potential spillover traffic to their would-be neighbors. It is a calculation that proprietors must do for themselves, but there is a coordination function that a good entrepreneur can serve, matching businesses that attract walk-ins with compatible stores, and maybe subsidizing (lowering the rent for) those that generate more spill-over traffic than they attract.
There are three seeds:
* A concentration of people (customers, though they need not be spending money, that helps)
* A concentration of stuff (suppliers, who need not be selling)
* An environment that encourages people to spend time doing stuff (marketplace)
People concentrate for a variety of reasons – to exploit the material resources of the earth, to have safety in numbers, to find a pool of potential mates, or simply because it is at the intersections of routes between two other places. These intersections (nodes in transportation lingo), create opportunities. In the streetcar era, people might change lines at a node, and those pedestrians would create the streetlife necessary to support new businesses. In the highway era the scale changed, and nodes are the interchanges of freeways. Businesses, and especially shopping malls, take advantage of these points of high accessibility. But the shopping mall is now clearly the destination, not a side-product of a transfer point in the same way street-car corners were.
Some further assertions about human nature:
People like pleasant climates – dry, not too hot, not too cold, clean air, not too loud.
People want to feel safe – they don’t want a car careening out of control disturbing their sidewalk café meal, they don’t want to think they will get run over crossing the street.
People are lazy – they don’t want to walk too far to get where they are going. If they are driving, they want easy convenient parking near their destination. They like to cross the street midblock and don’t want to have to walk to intersections.
People are cheap – they don’t want to pay for that easy convenient parking, they prefer lower to higher prices for the same good.
The last two be summarized by the idea that “People take the path of least resistance�?.
Observing cities around the world with an informed, but casual analysis leads me to assert some rules about the environment that lead to vibrancy.
Buildings on the sidewalk – vibrant areas have buildings that abut sidewalks with not large gaps between the building and the walk. The density of activity is necessarily reduced by space between building and path (and thus other buildings).
Sidewalks on the street – to have vibe, sidewalks must abut the street, or *be* he street in pedestrian only areas. Pedestrian only areas can work, and anyone who says otherwise has other interests at heart. This does not mean that they will work, but given the right environment, people would prefer to shop without having to look out for motorized vehicles.
Streets move slowly – fast streets make pedestrians feel unsafe, and thus reduces the benefits of being on the sidewalk. Ideally streets are moving at pedestrian speed in the pedestrian area. Of course streets leading to the pedestrian area move faster, or people could not get there.
Vehicle space on the street is minimal – wide streets increase the distance pedestrians must walk to reach other activities. Narrow streets give access to more stuff in less time. Hence the reason many enclosed shopping malls work better than many shopping streets is the density of stuff is fairly tight.
Street two way – One way streets may not be inherently problematic, but one-way streets are generally that way to move more vehicle traffic faster through the area, which is the opposite goal of moving pedestrians between buildings within the area.
Opportunities to explore just around the corner – hidden (pleasant) surprises are one of the things that make cities interesting to be in, if I go around this corner what will I discover. The same opportunities do not exist in an enclosed shopping mall, where everything is pre-mapped and tightly controlled, and I know each “block” ends at a parking ramp. Hidden unpleasant surprises however are one of the things that can kill a city, I don’t want to experience dread when I walk down an alley attached to my favorite shopping street.
This set of rules is by no means complete, but rules like these created streetlife in streetcar era places, and they create vibe in the better shopping malls.