New fuel cell prototype could power rural ITS applications

Intelligent transportation systems (ITS) technologies can be used to enhance transportation safety and mobility, but the sensors and communications equipment needed for ITS applications typically require access to electricity. In rural areas, limited access to the power grid can make it challenging to implement ITS devices.

Rural intersection roadway lighting
In addition to powering ITS devices, the fuel cells could provide power for rural
intersection roadway lighting. Photo source: http://www.flickr.com/photos/36521983488@N01/175482261/

Current solutions for providing power to off-grid locations include battery packs or diesel generators, both of which require constant maintenance to recharge, refuel, or replace. Other alternatives include solar panels and wind turbines, but cost and performance concerns have limited their use.

“One of the issues with these green power alternatives, such as solar panels, is dependability… especially in the long, cold, and dark Minnesota winters,” says Victor Lund, a traffic engineer with St. Louis County Public Works. Until this technology matures, there is a need for other options that can provide confidence in generating power, Lund says.

To provide a more effective and dependable power alternative, researchers from the University of Minnesota Duluth (UMD) have developed a portable prototype system that uses hydrogen-based fuel cells to generate electricity. The UMD research team was led by chemical engineering associate professor Steven Sternberg, and the project was sponsored by the ITS Institute at the University of Minnesota.

The hydrogen-based fuel cell provides a clean, compact, high-efficiency energy source for an accompanying battery pack, which could be used to operate various ITS devices. The prototype is completely independent of the power grid, works well in cold weather, and requires maintenance only once each week for recharging. The cost of the system is about $7,500, with an additional operating cost of $2,000 per year for fuel materials.

Potential applications include powering variable message signs, dedicated short-range communication technologies, and warning blinkers on traffic signs. According to Lund, the system’s applications extend beyond powering ITS devices. For instance, the fuel cells could be used for rural intersection roadway lighting or as a back-up source for traffic signals in case of a power outage.

Reprinted from CTS Catalyst, June 2013.

Permeable pavements could protect the environment, save taxpayer dollars

KSTP has a nice story today on the Minnesota Department of Transportation’s ongoing research into permeable pavements at the MnROAD research facility. (The video isn’t embeddable on WordPress, but you can find a direct link here.)

Permeable pavements (also known as “porous” or “pervious” pavements) are designed to allow water to pass through roadways and infiltrate directly into the underlying aggregate and soil. Their primary effect is to reduce stormwater runoff, which carries harmful materials from the road’s surface out into waterways. Of course, reducing runoff also mitigates the need for the kinds of costly drainage structures that are normally required to manage stormwater. Permeable pavements also reduce noise and mitigate the potential for hydroplaning, among other documented benefits.

These types of pavements are already used in some areas in Minnesota — mainly in parking lots and city streets — and MnDOT has been studying their potential use for full-depth roadway pavements. As the video indicates, so far the results have been encouraging. (You can read more about MnDOT’s ongoing research on the MnROAD website.)

As a side note, the amount of water these pavements can absorb is quite impressive. Last month, we posted a new Local Road Research Board video on stormwater management. In one scene, a public works crew dumps what appears to be several hundred gallons of water onto a permeable pavement and watch as it disappears almost instantaneously. (Watch the clip here.)

Here are the results of some recent permeable pavement studies here in Minnesota:

Quality-of-life study helps MnDOT evaluate performance measures

As part of a study on transportation and quality of life, MnDOT has partnered with researchers from the University of Minnesota’s Tourism Center to compare current MnDOT performance measures with quality-of-life factors that matter most to Minnesotans.

driver

The evaluation was designed to help MnDOT ensure alignment between the factors that best predict transportation satisfaction among Minnesota citizens and the indicators MnDOT uses to track and measure its performance. The study team was led by Ingrid Schneider, Tourism Center director, and Karla Rains, director of customer relations at MnDOT.

To conduct the evaluation, the research team first analyzed data collected using surveys and focus groups in a previous phase of the quality-of-life study. The data included information on the categories that contribute to quality of life in Minnesota, the role of transportation, and the specific factors or services within transportation that affect citizens’ quality of life.

From these data, the team identified a list of key transportation elements that drive customer satisfaction. Results indicate that the most significant predictors can be grouped into three categories: maintenance/safety, mobility, and transparency. Within those categories, 11 specific items—such as snow and ice removal, road smoothness, commute time, and satisfaction with long-term planning—account for 56 percent of the differences in citizens’ transportation satisfaction.

The team then compared the factors most important to Minnesota citizens with MnDOT’s current performance measures. Overall findings indicate that these existing measures, which track performance in nine major areas, broadly capture much of what is important for Minnesotans’ transportation-related quality of life.

“This was an important key finding for us—we’re already measuring and reporting on many of the things that matter most to our customers,” Rains says. “It was encouraging and comforting to see that.”

In addition to affirming MnDOT’s existing measures, the evaluation identified a few gaps, specifically in the areas of safety, the environment, and transparency.quality

For example, MnDOT typically reports transportation safety in terms of total traffic fatalities and serious injuries from vehicle crashes. However, the quality-of-life study revealed citizen interest in a broader view of traveler safety. As a result, MnDOT plans to include bicycle, pedestrian, and railroad-grade crossing fatality data in future performance measures. “This is already data that we track, but now we plan to add more reporting of fatalities by mode than we have included before,” Rains says.

Based on other study-identified topics of importance, MnDOT plans to add new performance measures focused on air pollution and conduct more reporting of information related to public trust.

“We continue to use this data as guidance in our planning, and it continues to be useful,” Rains says. “We want to make sure we’re listening and measuring ourselves against the things that are most important to our customers.”

Reprinted from CTS Catalyst, June 2013.

About those roundabouts

One of my unofficial duties as a MnDOT employee is to respond to a near-constant barrage of opinions from my family and friends regarding the condition of our state’s roadways. (My wife, for example, half-jokingly tries to ascribe personal responsibility to me for the congestion she faces on her morning commute.) Interestingly, one of the issues that gets brought up to me most often in private conversations is roundabouts — the circular intersections that are widely praised by engineers but often vilified by a skeptical public.

From a public interest perspective, the verdict on roundabouts is overwhelmingly positive. With very few exceptions, roundabouts have been shown to dramatically reduce both the frequency and seriousness of traffic accidents when compared to other types of intersections. One oft-cited source, the National Insurance Institute for Highway Safety, reports that U.S. intersections converted to roundabouts have experienced a 35-47 percent decrease in crashes and an 72-80 percent decrease in injury crashes (source here). Moreover, because the don’t have stop signs or traffic lights, roundabouts have been found to reduce traffic delays and pollution.

Perhaps not surprisingly, research on these potential benefits has precipitated a rash of roundabout construction. In Minnesota alone, 115 have already been built, with another 39 either planned or under construction, according to the Pioneer Press. Love them or hate them, roundabouts are becoming a fact of life here.

Of course, not everyone loves them. In spite of their stellar  record, roundabouts remain something of a political lightning rod. This article in the Mankato Free Press and this news segment from KSTP provide typical examples of the kind of skepticism officials face when proposing to put in a roundabout. The problem is persistent enough that many officials see a need to develop a public relations game plan. On June 19, the Transportation Research Board is offering a free webinar entitled “Community Outreach: Successful Outcomes for Roundabout Implementation,” designed to help transportation professionals understand and respond to political opposition to roundabouts. It’s free for employees of TRB sponsor organizations (including MnDOT); a $99 registration fee is required for employees of non-sponsors.

For those who are unfamiliar with roundabouts, there are some good resources designed to help people understand their purpose and benefits. Several years ago, the Local Road Research Board produced the video above (along with an accompanying brochure). MnDOT also has a resource page devoted to explaining the use of roundabouts.

Those with more than a passing interest in the subject might also want to check out these recent MnDOT/LRRB-sponsored studies:

Advanced hybrid buses have better fuel economy, fewer emissions

One of Metro Transit’s new advanced “super hybrid” buses—built in Minnesota and billed as the cleanest, most efficient diesel-electric hybrid buses in the United States—garnered national attention at the American Public Transportation Association’s Bus and Paratransit Conference May 5–8 in Indianapolis.

Photo of superbus
Photo: Metro Transit

Unique because of its all-electric accessory systems, the bus was featured at the event so that transit professionals from across the country could experience this new hybrid technology firsthand, says Chuck Wurzinger, assistant director of bus maintenance at Metro Transit. The bus is one of two advanced hybrids built for Metro Transit in 2012. They currently operate on local routes with frequent stops in downtown Minneapolis and its surrounding communities.

The decision to purchase the new hybrids was greatly influenced by the results of a University of Minnesota study aimed at improving fuel economy in diesel-electric hybrid buses, Wurzinger says. The “Superbus” study, led by mechanical engineering (ME) professor David Kittelson, included an energy audit of major accessory systems on a standard hybrid bus. The study was funded by Metro Transit, CTS, and the U of M’s Institute for Renewable Energy and the Environment (IREE).

Study findings indicated that up to half of the fuel consumed by hybrid buses is used to power accessory systems. According to the research team, powering these systems electrically could significantly improve fuel efficiency.

The new advanced hybrids do just that, using all-electric systems to power the heating, air conditioning, engine fans, power steering, and air compressor. These components improve fuel economy, reduce emissions, and allow the buses to be operated in electric-only mode for short periods.

Photo of Metro Transit diesel-electric bus
Photo: Metro Transit

One of the buses also has start/stop capabilities, which allow the engine to shut down at bus stops and traffic lights. “This reduces engine idle time while maintaining all other bus functions, including passenger comfort and safety features,” Wurzinger says.

Although the buses have been in service for only a short time, they are already showing promising increases in fuel economy, Wurzinger says. “We have also operated them consistently on electric power inside the bus garage, which helps keep the air clean in the building. This reduces the amount of ventilation required in cold weather, which means less energy is used to heat the building.”
Metro Transit has more than 130 hybrid buses in services--about 15% of its total fleet

Along with a standard hybrid bus and a conventional diesel transit bus, one of the advanced hybrids will be monitored and evaluated in a new study conducted by U of M researchers in collaboration with Metro Transit. The multidisciplinary research team includes Kittelson, ME associate professor Will Northrop, ME research associate Winthrop Watts, and applied economics associate professor Steven Taff.

As part of the study, funded by IREE, the team will collect real-world, on-the-road data from the three buses in all seasons on a variety of route types. The researchers then plan to compare the efficiency and emissions of the buses and make recommendations to Metro Transit about which configuration is the best for a given application. Data collected from the study will also allow Metro Transit to work with bus manufacturers to optimize bus performance.

“We believe the results will be useful in writing bus technical specifications and also in determining if a certain type of bus is best suited to a certain type of bus route,” Wurzinger says.

Ultimately, this information could be used to determine which buses to assign to which routes as well as which type of bus to purchase given fleet replacement or expansion requirements.

The project is scheduled for completion in 2015.

Reprinted from the CTS Catalyst, June 2013.

Construction kickoff at MnROAD, the state’s high-tech road research facility (updated)

*Editor’s note: This article was updated 6/11/13 with additional information provided by MnROAD engineers.

You’re probably aware that MnDOT recently kicked off its 2013 construction season, comprising $1.1 billion in new transportation investments in more than 300 projects across Minnesota. What you might not know is that another MnDOT construction season has begun at MnROAD, the department’s unique, high-tech pavement test facility located near Albertville, Minn.

MnROAD serves as a proving ground for innovative pavement designs, equipment and construction techniques that help transportation professionals all over the world strengthen roads, cut costs, and reduce construction times. It has a two test tracks — a 3.5- mile mainline carrying “live” traffic and a 2.5-mile closed-loop, low-volume roadway — that are used for state, university and private industry pavement research. These tracks are made up of dozens of individual “cells,” which are unique stretches of pavement each representing several research projects.

This summer, several test cells are being torn up and repaved. Cell 40, a 20-year-old concrete pavement, will receive an innovative 3-inch thick unbonded concrete overlay.  To increase the capacity of such a thin overlay , a fiber-reinforced concrete mixture will be used.  To separate and cushion the thin overlay from the existing concrete, two different thicknesses of nonwoven geotextile fabric will be laid.  This will help MnROAD researchers to understand how much cushioning is needed, as well as the drainage capacity of each fabric.  Fabric interlayers are gaining popularity as an alternative to asphalt interlayers.

Thin concrete overlays of asphalt, commonly known as whitetoppings, will also be used to reconstruct Cells 60-63.  Similar to Cell 40, fiber reinforced concrete will be used to test its benefit in supplementing load transfer at joints and across cracks.  Pavement built with this material will be strengthened by the fiber, prolonging a road’s lifespan, and potentially allowing for thinner concrete pavements.  Findings from Cells 40 and 60-63 support the ongoing development of improved design procedures for concrete overlays.

Cell 13 reconstruction is using recycled concrete aggregate provided by the contractor’s stockpile from other pavement projects. The concrete from the stockpile will be included in the concrete mix — a new practice to understand how to better recycle paving materials and ascertain the cost and benefits of this practice. Cell 13 will also be testing two innovative types of preformed joint sealants, and several joints drained by geotextile drains.

Construction updates are available on the MnROAD website as well as information regarding current research projects.

Image from MnROAD's 2013 construction kickoff.
Removing concrete in MnROAD Cell 13.

‘Three Ways to Cook a Pothole’

In April, we posted about an innovative pothole-filling technology being developed by the Minnesota Department of Transportation and the University of Minnesota, Duluth. The technique involves zapping pothole patches and the surrounding pavement with a special truck-mounted, 50,000-watt microwave. Researchers have found that heating the base and the patch material at the same time creates a stronger, longer-lasting bond that provides for a more permanent pothole fix.

Last week, the MnDOT/UMD microwave technology found its way into a new MnDOT video (above) that also explores two other experimental pothole-patching methods. One involves using a large “electric oven”-type heating element instead of a microwave. The other utilizes a new exothermic (i.e. heat-generating) asphalt mixture containing taconite from northern Minnesota mines. The video compares the potential benefits of all three of the new technologies, which the department hopes will someday lead to “more pothole-patching power for the taxpayer dollar.”

See also:

New flatwork specs ensure higher quality for local concrete projects

Placing concrete streets, sidewalks, curbs, and gutters just got a lot easier for cities and counties—and the inspectors, engineers, and contractors who work on them in Minnesota. Locals no longer have to adapt to the rigorous Minnesota Department of Transportation (MnDOT) specifications for trunk highways.

The Minnesota Concrete Flatwork Specifications for Local Government Agencies tech memo was issued by the MnDOT Office of State Aid in 2012. These specifications guide all State-Aid-funded local concrete projects and should reduce the confusion and misunderstanding that arose when engineers and contractors used different interpretations of the highway specifications.

The new specs require two people to hold a current ACI Concrete Flatwork Technician certification, with at least one on-site for all concrete pours.

Read more in the May 2013 issue of the TERRA E-News

New publication highlights success in traffic safety

Cover of TZD Decade of Progress reportThe Minnesota Toward Zero Deaths program has published Minnesota TZD: 10 Years of Progress (PDF), a 12-page report highlighting the program’s successes in the decade since it began. Before 2001, efforts to improve traffic safety were mostly carried out by individual state agencies. In response to an increasing trend in the number of traffic-related fatalities and serious injuries in the state, the Minnesota Departments of Public Safety, Transportation, and Health in 2003 established the Toward Zero Deaths (TZD) program to integrate safety programs in Minnesota. Since then, traffic fatalities have decreased by 40.5 percent. This report describes some of these efforts in the areas of driver behavior, roadway environment, emergency response, and partner collaboration.

CTS Research Conference videos and presentations now available

If you weren’t able to attend the CTS Research Conference, or, if you simply want to check out presentations from other sessions, the videos of the keynote and luncheon speeches, as well as PPTs from most of the concurrent sessions, are now available on the CTS website. You won’t want to miss Minnesota Department of Health Commissioner Ehlinger’s tuneful take on the links between health and transportation and Elizabeth Deakin’s view of new ways to get around.

Minnesota transportation research blog