Tag Archives: traffic

Raising speed limits doesn’t lead to faster driving

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I’ve seen several articles about this lately as several states consider raising highway speed limits: raising the speed limits does not lead more people to drive faster.

Traffic experts say that motorists tend to drive at a speed they feel comfortable, regardless of the posted speed limit. And according to Michigan Department of Transportation spokesman Rob Morosi, comfortable drivers generally make for safe roads.

“There’s a misconception that the faster the speed limit, the more dangerous the road,” said Morosi, “and that’s not necessarily true. Speed limits are most effective when the majority of people driving are comfortable at that speed.”…

Common sense, then, would suggest that increasing a speed limit would lead those motorists to increase their speed at a similar rate. But Megge, pointing to I-96 in Flint as a striking example, says that belief is not supported by the research.

Before 2005, traffic studies indicated that most motorists were traveling the Interstate at roughly 73 mph, he said. After the speed limit was increased, most motorists still traveled the Interstate at roughly 73 mph.

“When we raise a speed limit, traffic speed does not automatically increase. That’s a myth,” Megge said. “I’ve been doing this 15 years and raised 300 speed limits, and never have we seen or observed a wholesale increase in traffic speeds. It’s a very counter-intuitive idea. But the science and engineering works. We want to ensure it’s safe and fair to the public.”

Common sense approaches often don’t apply to traffic. This finding about speed limits fits with another finding about traffic signs: drivers don’t necessarily pay attention. Read about several places in Europe that have no traffic signs and few traffic markers and safety improves. In the case of driving speed, drivers seem to pay more attention to nearby drivers rather than the official speed limit. So even as people often drive solo and might argue their actions on the road are the result of their own individual choices, driving is indeed a social activity.

Here is a second good example regarding traffic that counters “common sense” or common behavior: using all possible lane space to merge is more efficient for everyone rather than having drivers block off lanes that will soon close.

 

Observed in Manhattan: online shopping leads to more traffic

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A graduate student in Manhattan argues that more online shopping leads to more traffic issues on the dense island:

Consider it this way: people around the world seem to have a travel time budget of a little over an hour each day. Before the rise of e-commerce, part of that time would have been spent in the service of purchasing goods. But if that budget remains fixed, then people today may simply buy something online, then hop in a car and go visit a friend across town. In that scenario, personal travel stays constant while commercial travel increases — a net gain of people and goods on the road…

Woodard’s case studies of the Gehry and three other residential apartments in Manhattan found the answer to those questions may very well be yes. Surveying the buildings for several hours at a time in the middle of the day, Woodard found that, on average, delivery trucks stayed parked for 21 minutes at a time, and two-thirds of them were double-parked. Extrapolating the data over a full day, in the case of the Gehry, that means delivery trucks alone occupy road space that’s not a true parking space for seven full hours…

Though Woodard’s case studies were never supposed to paint an exhaustive portrait of the urban e-commerce problem, they do underscore how little is known about it. One study from way back in 2004 estimated that delivery trucks cause nearly a million hours of vehicle delay each year, but the stunning grown in online shopping since then (and the fact that companies like Amazon are reluctant to release their data) makes any precise estimate difficult. Many experts consider this process of moving freight that final mile to be one of the biggest forgotten problems facing modern cities.

At the core of the problem is street parking. In a dense urban area like Manhattan, where few buildings have the luxury of freight docks or loading zones, delivery trucks have little choice but to park at the curb. That leaves passenger vehicles and delivery trucks to duke it out for precious street-parking space, which in turn leads to double-parking, which in turn leads to general congestion.

Interesting question and findings. How much do they apply beyond Manhattan, a dense place?

One issue not addressed here: how much do commerce companies bear responsibility for this congestion? Shopping online is often viewed as cheaper and more convenient but this analysis suggests there are some hidden costs that someone has to pay for. Roads are public goods paid for with tax dollars. If they are causing more congestion, could they bear some of this cost?

Chicago tries out a “pedestrian scramble” intersection

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Chicago has started testing the “pedestrian scramble” at a Loop intersection:

The changes center on a new pedestrian crossing pattern – dubbed the “pedestrian scramble” – that will be introduced at the intersection of State Street and Jackson Boulevard…

The test involves stopping all vehicles – heading east on Jackson and north and south on State – for about 14 seconds every other light cycle to give pedestrians a jump on traffic to cross in all directions, including diagonally, according to Bill McCaffrey, a spokesman for the Chicago Department of Transportation.

Developed more than 70 years ago, the pedestrian scramble allows pedestrians a running start to cross six ways instead of four ways.

The experiment is part of a larger plan by Chicago Transportation Commissioner Gabe Klein to reduce speeds and the number of vehicle travel lanes on busy streets in an effort to slash the number of crashes…

Klein’s strategy involves narrowing some streets, or putting them on a “road diet.’’

Two quick thoughts:

1. This reminds me of photographs of busy intersections in Tokyo where you see mobs of people crossing at all angles. See short videos here and here. Indeed, other countries have used pedestrian scrambles for decades.

2. People may not like the idea of a “road diet” but there is evidence that reducing traffic capacity could be more effective at dealing with traffic and congestion rather than continually expanding roads. Plus, you then get the side benefit of more safety and convenience for pedestrians and cyclists.

What Naperville residents like, dislike about the suburb

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A recent survey of Naperville resident shows what they like and what they don’t about the community:

The 2012 community survey was Naperville’s first in four years, netting 1,581 responses that will be used to create a strategic plan this summer…

The survey found 91 percent of respondents were satisfied with the overall quality of life in Naperville. Looking at city services, 92 percent were satisfied with fire and emergency medical services, 85 percent gave good marks to garbage and recycling services and 84 percent were satisfied with police services. Overall city service satisfaction levels were consistent no matter which part of town the resident lived in…

Traffic flow fared the worst with only 40 percent of residents saying they are satisfied, which is a 10 percent increase from the previous survey…

Compared to the rest of the country the city scored at or above the national average in 36 of 44 areas like overall quality of city services, city streets, sidewalks and infrastructure and overall image of the community. Residents’ satisfaction with overall quality of city services rated 32 percent above national average.

The city scored below the national average in eight areas including traffic flow, public transportation and household hazardous waste disposal service.

The national comparisons are pretty interesting here. The article goes on to suggest this is due, at least in part, to effective planning and responses from the city. This is likely true to some degree; Naperville sees itself as a leader for providing efficient and effective local services. On the other hand, I wonder how much of this is due to the relative wealth of Naperville. Considering its size, Naperville is unusually wealthy with plenty of good jobs which can then lead to good schools and more money for quality of life concerns like parks, libraries, parks, and lots of retailers.

The traffic issue is a tough one to solve in Naperville. Of course, much of the suburb is made up of auto-dependent neighborhoods. Couple this with Naperville’s wealth of jobs and attractive downtown and there is plenty of driving around. The city has three highways on its edges, I-88 on the north, I-355 on the east, and I-55 on the south, but the local main streets are quite clogged. This is an issue particularly going north-south as Route 59, Washington Street, and Naper Boulevard are quite crowded. Mass transit is available to Chicago, and Naperville has two of the busiest stops in the entire Metra commuter system, but transit is limited within the city outside of some shuttles to and from the train stations. I think the real question is whether the traffic in Naperville is bad enough for residents and business to not locate or stay in the community. If a number of the other indicators are so high, I would think not but bad traffic, particularly in auto-dependent places like big suburbs, can be quite irritating.

Strong suburban reaction to a roundabout turns to praise

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I was struck by a reaction of a few Lake County residents to a roundabout built several years ago:

When the first roundabout was proposed in Lake County, the response was extreme.

“People were so skeptical, I would seriously get phone calls from people saying there would be deaths at that corner and it would be on my conscience,” recalled Lake County Board Member Ann Maine, of Lincolnshire, who is also president of the Lake County Forest Preserve District.

More than two years after the roundabout opened at Everett Road and Riverwoods Road as an alternative to a traditional intersection, Maine said she hasn’t been stuck in a backup at the intersection and gets occasional notes from people who say they love the change.

That is quite a reaction to a roundabout and the favorable comments afterward are notable. There are studies about such things but I’m guessing those who had such a strong reaction to the roundabout either didn’t read such studies or wouldn’t believe their findings anyway. But, it is just a different way of configuring an intersection that most people get used to fairly quickly and can actually be more efficient.

An English town that got rid of its traffic signs and lights sees improvement in street life

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This idea is not unknown but it is still highly unusual: an English town recently removed all of its traffic signs and lights.

The village of Poynton in the U.K. has undertaken one of the most ambitious experiments to date in this type of street design, whose most prominent advocate was the Dutch traffic engineer Hans Monderman. Variations on the shared-space model have been implemented in other European cities since the early 1990s, but never before at such a busy junction. Poynton’s city leaders sought the change because the historic hub of their quaint little town had become a grim and unwelcoming place…

The project didn’t come cheap, costing about $6 million. Engineers completely reconfigured the intersection at the center of town, replacing a traffic light with two “roundels” that cars must negotiate without the guidance of traffic signs. Pavements of varying colors and textures are the only signal as to which type of road user belongs where.

It was a controversial move for the community of some 14,000 people, which lies about 11 miles from Manchester in the northwestern part of England. Now, a year after construction wrapped up, a video called “Poynton Regenerated” makes the case that the shared space scheme maintains a smooth flow of traffic while simultaneously making the village center a more attractive and safer place for pedestrians, leading to increased economic activity downtown…

In the “Regenerating Poynton” video, several people who admit to having been skeptical of the plan say that after it was put in place, they came to see it as a dramatic improvement. A local city councilor says that the main street no longer seems like a dying place, as it had for years before the change. Some 88 percent of businesses in the area are reporting an increase in foot traffic, and real estate agents say they’re seeing new interest in buying property in the area.

The social interactions that result from shared space — eye contact, waves of thanks, and the like — are one of the main selling points for advocates.

What is most interesting about this presentation is that it is less about safety, and traffic crashes do tend to go down when measures like this are taken, and more about how it can improve street life. When motorized vehicles are no longer privileged on the streets in the ways that they are in most communities, street life can be more open and lively. So, perhaps we will see more people in the coming years selling this plan more as a viable redevelopment option rather than a safety concern.

Will a new design for Chicago’s Circle Interchange prove beneficial in the long run?

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Illinois and Chicago officials are putting the final touches on plans to reconstruct the Circle Interchange where the Eisenhower, Kennedy, and Dan Ryan expressways come together. But, will a new design lead to better outcomes?

But other urban planning experts criticized the agency’s decision, saying the claimed benefits of the Circle project were not put to a rigorous test. For instance, it’s highly unlikely that IDOT’s estimate of at least a 50 percent reduction in traffic delays on the three expressways would materialize, some independent experts said.The Circle project also scored poorly on criteria designed to determine whether ridership on public transit and access to transit would be enhanced by the work, the experts said.

“The data that CMAP made available showed that this project would not produce a significant return on investment,” said MarySue Barrett, president of the Metropolitan Planning Council, a nonprofit group that promotes sustainable transportation and land-use policies…

IDOT officials insist that Alternative 7.1C would do the best job of reducing congestion, bottlenecks and crashes, leading to faster and safer commutes, according to traffic modeling that simulated the estimated 400,000 cars and trucks that travel over the Circle Interchange each weekday.

An average of almost three accidents a day occur in the vicinity of the Circle, which is also the slowest and most congested highway freight bottleneck in the U.S., according to the Federal Highway Administration.

It sounds like there are actually two conversations going on:

1. How to improve this specific stretch of road. The primary emphasis seems to be on adding lanes, both for the Kennedy and Dan Ryan through the area as well as for the congested ramps. Of course, adding lanes it not necessarily a panacea – drivers tend to fill in the supply that new lanes provide.

2. How this stretch of road fits in with larger traffic concerns in the Chicago area. It is one thing to reduce congestion at this particular point but another to improve mass transit on a broader scale that would help reduce demand for this traffic bottleneck. Traffic could be viewed as a region-wide issue where policymakers could try to reduce the number of highway trips through this area. Some would argue Americans have tended to privilege trying to fix roads rather than tackle the larger issues of why congestion occurs in the first place.

Four years of major construction is a long time to wait if the alterations don’t change much in the long run…

Some proposed solutions to the problem of 947,000 hours a year in traffic lost to parcel delivery trucks

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Cities are looking into ways to better facilitate parcel delivery than having trucks park along the curb:

Over the last couple of years, urbanists have dreamed up a handful of new parcel delivery strategies. A number got a field test in Europe last year as part of CITYLOG, a project funded by the European Union to evaluate fresh ideas in urban transport.One of these new strategies, the BentoBox, works by shifting delivery truck activity away from peak driving hours. If congestion reduction is the goal, the ideal time to deliver packages would be late at night—but customers won’t likely be smiling when they answer the door. Named after a single-serving Japanese takeout tray, the BentoBox is a storage locker that can be loaded with parcels and then dropped off at a local docking station after hours. Customers in the area can access one of six subdivided units with a key the following morning…

TNT Express has its own program aimed at piloting urban delivery solutions. In Brussels, where the courier company delivers about 1300 parcels per week, three-quarters of those deliveries are already made using pedal-assisted electric tricycles. These small vehicles are more environmentally sound than large trucks and vans, and much less disruptive to traffic patterns when parked.

TNT is modeling a new distribution model for Brussels that it calls the “mobile depot.” In this system, which works similarly to the BentoBox, a trailer containing a large number of parcels is towed to a central location in the city during off hours. Parcels are delivered by last-mile drivers in small electric or human-powered vehicles. If a few of these mobile depots could be dropped in strategic locations around the city, package trucks, which currently use surface streets and highways en route to distribution hubs located outside the city, could be eliminated.

The “mobile depot” idea sounds interesting but it might be difficult to find suitable distribution sites within cities. This idea reminds me of the rail traffic problems in the Chicago area where the solution in recent years has been to keep moving distribution facilities to areas further away from the core of the region. But, new distribution sites could inconvenience certain neighborhoods or areas while providing a benefit to the city or region.

I wonder if this is similar to adding lanes on highways: if delivery trucks are taking up less space, will more cars fill the space?

How much do McMansions contribute to traffic congestion?

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After seeing the Washington D.C. region leads the country in traffic, one reader of the Washington Post suggests McMansions have contributed to the problem:

Regarding the Feb. 5 news article “Washington again rated worst for traffic congestion in annual study”:

I don’t understand. The entire metropolitan region builds, builds and builds, squeezing  condos onto every block and ruining old neighborhoods with ghastly McMansion and townhouse developments.

Do officials consider quality of life? Don’t they realize how these new homes have a tremendous effect on our local traffic? We have overbuilt this area to death.

It would be interesting to see a study on this. I suspect the real answer is not McMansions over other forms of housing and development but rather the issue of sprawl. McMansions may often be found as part of sprawl but not necessarily; McMansions don’t have to be built on large lots, which leads to more spread out development, and they can be built as teardowns in denser areas. But once sprawl has already happened, it is more difficult to provide effective mass transit (even as the Washington region sees an expansion of Metro service to suburban counties). In other words, McMansions are symptoms of sprawl which leads to a lot of driving and traffic.

The experiences of a passenger in a driverless car

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I have wondered about this: what is it like to be a passenger in a driverless car?

As we drove along Chicago’s South Lakeshore Drive, Muharemovic switched the car through three modes which can be selected based on what the driver wants and what the traffic situation entails…

Finally, there’s a Highly Automated mode that adds full-speed ACC with an automatic-resume function that uses free-space detection and side-sensing. This is the one we’re looking forward to.

In fully automated mode, Muharemovic completely removed his hands from the steering wheel and foot from the pedals. At one point he turned around for several seconds to talk to passengers in the backseat. He had a casualness that comes from getting used to the technology over thousands a miles and a steadfast faith in the systems he helped create…

A dyed-in-the-wool Detroit car guy, Muharemovic challenges anyone who fears that autonomous driving will take the fun out of motoring. “I’d like to meet someone who loves traffic jams,” he says, adding that his girlfriend has noticed that he comes home less stressed from his daily commute.

As this article suggests, it will likely take some time for drivers to feel comfortable letting the car do all the driving. But, once drivers see what their commute could be like, perhaps they would like the freedom.

Two other pieces of information I would like to have:

1. In fully automated mode, would traffic jams become shorter because traffic could be more evenly spaced? If so, this would be a double bonus: less traffic and not having to pay attention to whatever traffic there is.

2. I can only imagine what the early lawsuits might be like if one of these systems fails and an accident ensues or there is a glitch in the design. I was reminded the other day that nothing was ever found wrong with Toyota’s gas pedals yet they had to pay out millions in settlements. How much money could be on the line if an automatic system like this fails?