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Which Matters More — A Bike Network’s Connectivity or Its Density?

The "connectivity" of bike infrastructure a city has matters, but not as much as some other aspects. Image: University of Minnesota

Adding to total bike lane mileage without creating a denser network does not seem to affect ridership. Image: University of Minnesota

What’s the secret to designing a bicycle network that will get people riding?

A pair of researchers at the University of Minnesota recently set out to test the theory that a connected bike network — where bike lanes provide continuous routes between many possible destinations — is a major determinant of how many people bike. What they actually found was a little unexpected. Connected bike infrastructure matters, according to the study [PDF], but not as much as the density of bike infrastructure.

UMN’s Jessica Schoner and David Levinson used GIS software to map cities’ bike networks and rank them according to connectivity, size, density, and other factors. (“Connectivity” is basically a measure of the degree to which bike lanes intersect within a city, and “density” is a measure of bike lane mileage within a given area.) Then, using Census data, they determined the relationship between each factor and the number of people who commute by bike.

Bike lane density was the most important factor, with each standard deviation (about 1 kilometer of bike infrastructure per square kilometer) associated with an additional 150 bike commuters per 10,000 commuters. For connectivity, one standard deviation correlated to an additional 37 bike commuters. Other factors — the overall size of the bike network, the directness of routes within the system, and fragmentation (separate clusters of bike lanes within the same city) — were not shown to have a statistically significant effect.

Schoner and Levinson caution that correlation does not equal causation, so it’s unclear whether the dense networks enticed more people to bike, or if higher numbers of cyclists helped create denser bike networks. The study also did not distinguish between protected bike lanes, painted bike lanes, and off-street paths, so it does not account for the degree of separation between cyclists and traffic.

But the study does indicate that the density of bike lanes within a city could be an under-appreciated factor in getting more people to ride. “These findings suggest that cities hoping to maximize the impacts of their bicycle infrastructure investments should first consider densifying their bicycle network before expanding its breadth,” the authors concluded.

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TA: De Blasio Must Undo Construction Budget Cuts to Fix Dangerous Streets

The Grand  Concourse at 149th Street. Transportation Alternatives recommends major redesigns and significant investments in this arterial street and others.

What the Grand Concourse could look like with dedicated bus lanes and protected bike lanes. Click to enlarge. Rendering: The Street Plans Collaborative and Carly Clark for Transportation Alternatives

Arterial streets — the city’s big, busy, highway-like roadways — cover just 15 percent of the New York City street network but account for nearly 60 percent of all pedestrian fatalities. The city will have to overhaul these streets to achieve Mayor de Blasio’s Vision Zero goals. And to make those changes, the city must reverse cuts to its roadway reconstruction budget, according to a new report from Transportation Alternatives [PDF].

Arterial roads comprise 15 percent of NYC's streets but are the site of nearly 60 percent of the city's pedestrian deaths. Map: TA

Arterial roads comprise 15 percent of NYC’s streets but are the site of nearly 60 percent of the city’s pedestrian deaths. Map: TA [PDF]

Earlier this month, DOT announced that it will be committing $250 million to multi-year overhauls of Queens Boulevard, Fourth Avenue, Atlantic Avenue, and the Grand Concourse. TA urges the city to make that announcement a downpayment, not the final number. The report estimates that as many as 50 lives could be saved and 1,200 serious pedestrian injuries could be avoided each year if DOT redesigns all major arterial streets for safety.

At the city’s current rate of investment, however, it will take more than 100 years to fix the city’s arterial streets, TA says. The group estimates that Mayor Bill de Blasio’s preliminary budget drops funding for road reconstruction from an average of 47 lane-miles each year to 35 lane-miles each year. TA is asking the city to double its commitment, to $2.4 billion over 10 years. This would also ensure that streets do not fall into disrepair for decades before there is funding to rebuild them again.

In addition to more funding, TA recommends setting specific benchmarks and accelerating the timetable for implementation, with groundbreaking on the first arterial reconstructions by 2017 and a fast-tracked delivery plan. (Transportation Commissioner Trottenberg made promises to that effect earlier this month.)

Smaller projects that add curb extensions and road diets to targeted locations can have a big impact even without a complete road reconstruction. DOT has promised to complete 50 of these projects a year. TA is asking for an additional $50 million annually from the city budget to cover more ground in a shorter amount of time.

The report also recommends greater clarity from DOT about where it is looking to install safety improvements, and what changes will be pursued. That way, the public can ensure the agency’s plans align with the locations DOT identified in pedestrian safety action plans for each borough. Those plans identified 443 miles of dangerous corridors in need of safety overhauls.

Why is it important to fix the city’s arterial streets? In addition to making the city safer and less stressful for everybody, the implications are especially significant for New York’s most vulnerable residents. Studies show that low-income communities, seniors, and children are disproportionately affected by traffic violence.

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Just in From London: Congestion Charging’s Street Safety Bonus

Figure-4-from-London-paper-by-Green-et-al.-_-10-March-2015

After London’s congestion charge took effect in 2003, traffic crashes dropped much more sharply than in other U.K. cities. “Treatment” line denotes the charging zone. Control line is weighted average of 20 other urban areas, with data normalized to match pre-2003 crash data for charging zone. Graph: “Traffic Accidents and the London Congestion Charge”

Add street safety to the list of benefits from congestion pricing. That’s the takeaway from a new “working paper” analyzing traffic crash rates in and around the London congestion charging zone by three economists associated with the Management School at Lancaster University.

Traffic Accidents and the London Congestion Charge” slices and dices the monthly changes in crash frequencies since the 2003 startup of London’s congestion charge in nearly every way imaginable: daytime vs. nighttime (the charge is in effect 7 a.m. – 6:30 p.m.); weekdays vs. weekends (no charge during the latter); within both the 8-square-mile charging zone and each of two “spillover regions” two and four kilometers outside the zone; for charged and exempt road users; for fatal and serious injury crashes and all crashes; and vis-à-vis a control group of 20 other British urban areas. (The comparison group is necessary to control for declining crash rates throughout the U.K.)

The bottom line: Traffic crashes are significantly lower with congestion charging — by as much as 40 percent within the cordon zone. Crashes are down in the spillover regions as well; they declined not only for autos and trucks but for “uncharged” vehicles like taxis, buses, motorbikes and bicycles; and the improvement registered during non-charge times as well as the hours when the congestion charge is collected.

Here are key findings:

  • Traffic crashes within the charging zone are down by approximately 400 per year, relative to ongoing trends, corresponding to a 38-40 percent decrease — a reduction several times greater than the drop in vehicle miles traveled.
  • Within both spillover zones, crashes are 13-14 percent less than in the control cities, belying fears that rerouting of journeys and/or destinations would merely relocate traffic conflict and danger to areas outside the zone.
  • Even with considerable mode-shifting from cars to bicycles, motorcycles and taxis, crash rates for “uncharged” vehicles within the zone are 12 percent below those for the same vehicle classes in the control cities.
  • Crash rates inside the zone during non-charge hours are also significantly less than in the control cities, i.e., gains in safety haven’t been confined to the 55-60 hours a week in which congestion is charged but are spread across all 168 hours per week.
  • The congestion charge has led to an estimated 46 fewer serious and fatal crashes within the charging zone each year, including 4-5 fewer fatalities per year.

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RPA: Growing Outer Boroughs Need New Generation of Transit Investment

Subways, focused on service to and from the Manhattan core, have seen a 23 percent ridership boost since 2003. Over the same period, bus ridership, which forms the backbone of outer-borough transit, has fallen 6 percent. Image: RPA [PDF]

Subways, focused on service to and from the Manhattan core, have seen a 23 percent ridership boost since 2003. Over the same period, bus ridership, the backbone of outer-borough transit, has fallen 7 percent — even though population and jobs in the outer boroughs are growing at a faster rate than in Manhattan. Image: RPA

With the boroughs outside Manhattan adding people and jobs faster than the city core, New York needs to reorient its transit priorities, argues the Regional Plan Association in a new report. The authors warn that increasing travel in the other boroughs will strain the local bus system and lead more people to drive, causing more traffic congestion and imposing the burden of car ownership on more low- and middle-income New Yorkers.

This trend is already apparent. You could call it a tale of two trips.

Trips to and from the Manhattan core are shifting away from cars, with almost 90 percent of commuters to jobs below 60th Street arriving by transit. Subways, the backbone of the network into and out of Manhattan, have seen ridership increase 23 percent since 2003. Major projects are underway to extend subways and commuter rail serving the Manhattan central business district.

By comparison, transit trips that don’t begin or end in Manhattan are slower and less convenient, and they’re getting worse.

While the region may be centered around the Manhattan core, the lives of many New Yorkers are not: 61 percent of NYC workers who live outside Manhattan also work outside Manhattan. Over the last two decades, the number of jobs in the other boroughs has grown twice as fast as Manhattan-based jobs. At the same time, buses — the workhorse of outer-borough travel — have seen ridership fall 7 percent since 2003.

To avoid a future of even more sluggish transit and congested streets, RPA suggests new rail connections, more Bus Rapid Transit lines, and improving access to existing commuter rail service for city residents.

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10 Cities That Are Getting “Wired Transportation” Right

Image: Frontier Group, U.S. Public Interest Research Group

The Frontier Group and the U.S. Public Interest Research Group rated 70 cities on the availability of tech-enabled services like real-time transit information, ride-hailing, and bike-share. These are the top ten.

Which cities are making it easy to catch the next bus without a long wait, hail a ride with an app, or hop on bike-share? According to a new ranking from the Frontier Group and the U.S. Public Interest Research Group, Austin is leading the pack when it comes to embracing technological innovation that helps people get around without being tethered to a car.

The research team examined the availability of 11 types of technology-assisted transportation — like real-time transit information, ride-hailing services, virtual ticketing, multi-modal trip-planning apps, and bike-share — in 70 U.S. cities.

Some of them have penetrated nearly every market. For example, 68 metros have some form of peer-to-peer car-share that allows vehicle owners to rent their car to other people using services such as RelayRides. Services the authors call “ridesourcing,” like Uber and Lift, are available in 59 cities. Ride-sharing services designed to facilitate carpooling, like those offered by ZimRide or Carma, are only available in five cities.

Some form of bike-share is available in 32 cities, and 47 offer real-time transit data. Only six cities, Austin among them, have “virtual ticketing” that allows transit passengers to purchase rides using smartphones without cash.

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States That Ban Traffic Safety Cams Put Their Own Residents’ Lives at Risk

In France, speeding cameras are credited with saving more than 15,000 lives over seven years. Image: Accident Analysis and Prevention

Speed cameras are credited with saving more than 15,000 lives over seven years in France. Image: Accident Analysis and Prevention

In Ohio, lawmakers are now poised to outlaw traffic safety cameras, needlessly obstructing efforts to save lives. Similar bills were taken up this year in statehouses in Iowa, South Dakota and Missouri. According to the Governor’s Highway Safety Association, 12 states have laws that forbid speed cameras under most circumstances.

If enacted, these laws will certainly end up costing a lot of innocent people their lives. A 2010 review of dozens of studies indicates that speed cameras always have a positive effect on street safety, typically reducing fatality rates by around 30 to 40 percent where they are installed. One of the most impressive case studies, on a national scale, is France.

Since the French government began its crackdown on speeding about a dozen years ago, annual traffic fatalities have been reduced by more than half, from 7,242 in 2002 to 3,250 in 2013. That is more than double the rate of improvement in the United States over the same period. Researchers attribute a major portion of that reduction to the installation of about 3,000 speed cameras across the nation.

Following the adoption of a new set of street safety policies by President Jacques Chirac in 2002 — including stricter penalties for traffic violations — and the installation of cameras in 2003, enforcement of speeding increased dramatically, from about 100,000 tickets per month to about 500,000. About 87 percent of those citations were issued by cameras.

In a 2012 study in the Journal of Accident Analysis and Prevention, researchers set out to determine how many deaths and injuries were prevented by France’s wide-scale adoption of automated speed enforcement, developing statistical models to isolate the effect of the cameras. In the first two years following implementation, they estimate that speed cameras prevented 4,498 fatalities.

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The Parking Tax Benefit: A $7.3 Billion Subsidy for Traffic Congestion

Graph: TransitCenter/Frontier Group

Not only does the parking tax benefit pay people to drive during the most congested times of day, the whole system of commuter benefits functions as a gigantic transfer from poor workers to affluent workers, who have greater access to subsidized travel to work. Graph: TransitCenter/Frontier Group

The federal government spends billions of dollars a year on tax subsidies that make traffic congestion worse, according to a first-of-its-kind analysis by TransitCenter and the Frontier Group. The culprit is the parking commuter tax benefit, which costs taxpayers $7.3 billion in foregone revenue each year, all while adding more than 800,000 cars to rush-hour traffic on the nation’s roads each workday, the authors estimate.

The parking tax benefit allows people to claim up to $250 in parking expenses as tax-free income per month. It originated in the late 1970s, when, in the name of fairness, Congress prevented the IRS from taxing the free parking perks that employers gave their workers, without any thought to the effect on transportation. The new report shows that not only does the parking tax benefit have a disastrous effect on traffic, it’s not even fair to car commuters — amounting to a gigantic transfer to the most affluent drivers.

Most advocacy efforts centered on commuter tax subsidies attempt to raise the transit benefit — currently capped at $130 per month. Last week, for instance, two members of Congress pledged to fight for an equal commuter benefit for transit and parking. TransitCenter and the Frontier Group argue that this is the bare minimum to strive for. The real impact lies in simply getting rid of the parking benefit.

The transit benefit, they write, is a “relatively inefficient tool for motivating changes in transportation behavior” and “only weakly counteracts the negative impact of the parking tax benefit” — and should be thrown out, as it were, with the bathwater. If commuter benefits are retained, however, they recommend some key reforms: equalizing the transit benefit, and mandating that employers who offer parking benefits also provide the option of receiving a cash equivalent instead.

TransitCenter and Frontier Group estimate that while most people don’t change their commuting behavior based on the incentives created by these tax benefits, about 2 percent do — and that 2 percent drives 4.6 billion additional miles per year.

To make matters worse, they do that extra driving at peak hours, in crowded downtown areas, worsening congestion that the country’s transportation policy is supposedly oriented toward fixing.

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More Evidence That Adding Bike Infrastructure Boosts Biking

If you build it, they will bike. That’s the upshot of a new study from researchers at University of North Carolina-Chapel Hill, examining the effect of bike infrastructure.

Bike commutes rates around Minneapolis' Midtown Greenway soared over the last decade. Photo: Wikipedia

Bike commute rates around the Minneapolis Midtown Greenway soared over the last decade. Photo: Wikipedia

Researchers charted bike commuting rates across the Minneapolis area, finding, not surprisingly, that the biggest increases happened near the biggest investments in safe, comfortable bike infrastructure.

The research team examined cycling rates over a 10-year period among residents near the Midtown Greenway, an off-street bikeway running along the city’s south side, which opened in phases beginning in 2000.

They found that bike commute rates skyrocketed among people living within three miles of the greenway, from 1.8 percent to 3.4 percent — an 89 percent increase. Among people living father away, between three and six miles from the greenway, bike commuting rose at a more gradual pace: from 1.2 percent to 1.8 percent — a 50 percent increase.

“These data are supportive, but not proof, that a commitment to urban cycling infrastructure can increase active commuting by bicycle,” study author Penny Gordon-Larsen told the Obesity Society, a collective of scientists studying obesity. Previous research from Portland State University professor Jennifer Dill has shown that streets with bike lanes attract a disproportionate share of total bike traffic.

The findings of the study were presented to the Obesity Society at the group’s annual meeting earlier this month. The full study has not yet been published.

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Confirmed: Sprawl and Bad Transit Increase Unemployment

Since the 1960s and the earliest days of job sprawl, the theory of “spatial mismatch” — that low-income communities experience higher unemployment because they are isolated from employment centers — has shaped the way people think about urban form and social equity.

But it’s also been challenged. The research that supporting spatial mismatch has suffered from some nagging flaws. For example, many studies focused on job access within a single metropolitan area, so it wasn’t clear if the findings were universal. Other studies looked only at linear distance between jobs and low-income residents, not actual commute times. In addition, researchers including Harvard economist Ed Glaeser have argued that it’s difficult to determine whether neighborhood inaccessibility causes higher unemployment, or whether disconnected areas attract more people who have trouble finding work.

A new study [PDF] from researchers at the U.S. Census Bureau, the Comptroller of the Currency, and Harvard University, however, addresses those shortcomings and confirms the original theory of spatial mismatch: Geographic barriers to employment — sprawl, suburban zoning, poor transit — do indeed depress employment levels.

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Don’t Believe the Headlines: Bike Boom Has Been Fantastic for Bike Safety

safety in numbers 77-12 570

The Governors Highway Safety Association released a report Monday that, the organization claimed, showed that the ongoing surge in American biking has increased bike fatalities.

Transportation reporters around the country swung into action.

“Fatal bicycle crashes on the rise, new study shows,” said the Des Moines Register headline.

“Cycling is increasing and that may be reflected by an increase in fatal crashes,” wrote NJ.com.

“Bike riding, particularly among urban commuters, is up, and the trend has led to a 16 percent increase in cyclist fatalities nationwide,” reported the Washington Post.

Bike fatalities are a serious problem that needs to be tackled. The United States has dramatically higher rates of injury and death on bikes than other rich countries, and it would be appropriate for GHSA, an umbrella organization of state departments of transportation, to issue an urgent call to action to make biking safer. So it’s especially troubling that the main thrust of this report is complete baloney.

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