Safety with a Rumble

by Matt Mann, Research Program Coordinator

Centerline rumble strips have been shown to reduce lane departure crashes by as much as 25% on rural roads, and are now being installed on undivided, rural, two-lane highways in Massachusetts as appropriate.

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The sinusoidal rumble strip uses a wave-shaped rumble strip to create the noise and vibration necessary to alert the driver. (Road and Bridges, 4/3/2017)

Improving safety, at a low-cost, can reduce crashes and save lives. In the U.S., 60% of crashes on rural roads result in a fatality. Of these fatal crashes, approximately 90% are on two-lane roads. Lane departure crashes from vehicles crossing over the centerline on undivided, two-lane, rural roads have been proven to decrease with the installation of centerline rumble strips (CLRS). This reduction can be as high as 25% along certain rural roads, and even higher when CLRS are installed along with shoulder rumble strips (SRS).

Many factors contribute to drivers crossing over the center yellow line, including speeding, fatigue, and drowsiness, and distracted driving. Some common techniques on the roads now that try to mitigate lane departures and improve safety include, but are not limited to centerline and edge line pavement lane markings, higher retroreflectivity of traffic signs (for day and nighttime visibility), and vertical reflective panels. All of these have had some success. A number of studies, however, have shown CLRS to be more effective along certain rural sections of highways, in decreasing lane departures.

The purpose of CLRS is to prevent vehicles from crashing head-on or sideswiping each other. Vehicles tend to veer outside of their lane on all types of roadways, especially on undivided, two-lane rural highways where cross-over crashes are most common. CLRS can also act as a traffic calming tool. Similar in design to the rumble strips on the shoulders of Interstates and other limited access highways, CLRS are located along the centerline. With either placement, the objective of the rumble strips is to alert inattentive drivers that they are veering outside of their lane, and ideally help them correct this action before a crash occurs.

The main reason for CLRS’ effectiveness is their design, specifically the vibrations and noise when tires cross over them. However, this noise has also been a major reason why CLRS are not used on more roads. Abutters and businesses have complained about CLRS being too loud as vehicles cross over them. California Department of Transportation (CalTrans) and Minnesota DOT (MnDOT) have conducted research on creating effective, quieter CLRS. MnDOT has developed the sinusoidal wave-shaped rumble strip. Some study results have shown a decrease in noise levels outside the vehicle, as vehicles cross over these sinusoidal rumble strips, while the CLRS still maintain the effectiveness by alerting drivers of lane departures. In addition to noise, another concern of CLRS is the potential reduction of visibility of the centerline yellow strip, though, in a survey by the Insurance Institute for Highway Safety, some respondents reported that the visibility of the centerline yellow strip in the rain was better over CLRS than on flat pavement.

MassDOT, along with other DOTs, continues to develop and implement CLRS on their rural, undivided, two-lane highways. MassDOT currently considers implementing CLRS on an as needed basis. Decisions about where to install CLRS are based on a couple of variables, including lane departure crash data and land use (regarding the noise factor). As discussed with Bonnie Polin, MassDOT Highway Division Manager of Highway Safety, CLRS were recently included in a paving project along sections of Route 140 in Gardner and Winchendon. CLRS are easier and more cost effective to install when a roadway is being re-paved as was the case along Route 140. As MassDOT updates its Strategic Highway Safety Plan, CLRS are referenced as a safety measure to prevent lane departures.  MassDOT will continue to support and install CLRS on their secondary roads, where appropriate.

 

 

Massachusetts is Meeting Climate Change Head On

by Matt Mann, Reseach Program Coordinator

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State Street, Boston – City Lab

As weather events become more extreme, MassDOT and Massachusetts communities, especially those on the coast, recognize their infrastructure is vulnerable. Coastal cities and towns are currently grappling with the extreme climate impacts of higher temperatures, increased extreme precipitation and greater amounts of sea level rise. All of these impacts are not new, they have slowly been occurring over the past century.  It is predicted these changes will accelerate and increases will happen over a shorter length of time (e.g. by 2030, the sea level could rise by 4”-8” (BRAG Report, 2016)).

MassDOT and Climate Ready Boston presented at the April 2018 MassDOT Innovation and Mobility Exchange on the impacts to transportation assets and infrastructure, and strategies to better accommodate climate change. Mia Mansfield, Climate Ready Boston, presented on goals to guide Boston’s future growth:

  • Goal 1: Provide quality of life in accessible neighborhoods
  • Goal 2: Drive inclusive economic growth
  • Goal 3: Promote a healthy environment and adapt to climate change, and
  • Goal 4: Invest in infrastructure, open space and culture

Associated with these goals are planning and implementation projects for creating resilient infrastructure and buildings, preparing communities, and protecting shorelines. The feedback from the public outreach on what types of flood ready improvements the public would like to see included expanding open space, berm development, and flood walls. Project areas Climate Ready Boston has focused on are East Boston, Charlestown, and South Boston. Mansfield spoke about this initiative saying, “The resiliency strategy embraces layered flood control and integrated green infrastructure measures that mitigate the effects of climate change, and create social, environmental, and economic benefits and value to the people of East Boston and Charlestown and to all who share in the health of the city and the harbor.”

The existing transportation assets will be impacted by more flash floods, landslides, and flooding. Further, increased precipitation could have adverse impacts on the infrastructure that helps move the water, especially on culverts. Hongyan Oliver, MassDOT Office of Transportation Planning, and Chris Dorney, WSP USA, presented on MassDOT’s multi-year statewide Climate Adaptation Vulnerability Assessment study. This study aims first to identify a prioritized set of MassDOT transportation assets throughout the Commonwealth that is at high risk for future inland flooding, and second to provide actionable scientific information for adaptive strategies, and future capital and project planning. This second goal begins on a broader planning level and then is developed through a detailed analysis of vulnerable assets. One challenge is mapping statewide future floodplains where vulnerable assets are located. With this challenge in mind, MassDOT is currently conducting a pilot mapping study on a watershed in western Massachusetts. The approach is to prepare georeferenced data, assign slopes, calculate current peak flows and 100-year flows, elevations, and floodplains, and evaluate the asset exposure. Procedures for floodplain mapping will include developing an instruction manual, applying the data management protocol, and automating parts of the process for efficiency.

Next steps after that will include training additional MassDOT staff on the procedures, and applying the pilot study procedures and lessons learned from all other watersheds in the state and sharing the results and data with stakeholders.  Eventually, this important information and these strategies can then be incorporated into MassDOT’s project prioritization, capital planning, asset management system, and emergency preparedness procedures.

Hot Mix Asphalt Mixtures – What Works

by Courtney Murtagh, UMTC Intern, and Tracy Zafian, Research Fellow

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Road paving project in Lee, MA, 2010. (Source: blog.mass.gov).

Dr. Walaa Mogawer, UMTC Research Affiliate, Professor at UMass-Dartmouth, and UMass-Dartmouth Research Engineer Alexander Austerman recently published the results of their research study on Experimental Hot Mix Asphalt Projects Placed in Massachusetts. Professor Mogawer discussed this research topic in an Innovative Outlook interview in September 2017.

The study’s primary goal was to monitor roadway projects in the Commonwealth that used different experimental mixtures of asphalt to see which mixtures worked best, with the longest service life, best distress resistance, and easiest placement or construction. As described in the study report, the data gathered through this study can aid “Massachusetts in determining if full-scale implementation of these design methodologies and technologies is cost-effective in the long term. Overall, it is anticipated that well-performing technologies could be separated from poor-performing ones, thus leading to better decisions for future infrastructure.”

This study, conducted over a 5-year period (2012-2017), evaluated the performance of experimental hot mix asphalt (HMA) mixtures used in 12 different road pavement projects around Massachusetts. The 12 projects selected by MassDOT staff for this evaluation each involved new pavement technologies or new specifications. These technologies and specifications were tried for a variety of reasons, ranging from trying to mitigate reflective cracks in HMA layers placed over plain concrete slabs to the construction of environmentally friendly “green roads” by the incorporation of warm mix asphalt and ground tire rubber.

As described in the report, at the start of the study the researchers worked to collect all available data from MassDOT on each of the selected projects, including “all bid contract documents, material specifications, plant reports, construction quality assurance data, ride quality and distress data.”

The study then involved developing monitoring plans for each selected project, some of which had been constructed prior to the study. For each site, condition data were collected periodically throughout the duration of the study to quantify the performance of each mix and the changes in performance over time. Data were collected in the same manner for each project, using standardized techniques from MassDOT’s Pavement Management Section, such as surveying distress and calculating the relevant Pavement Condition Index (PCI). This ensured fair and consistent measurements and evaluations for each site.

The study’s primary conclusions and recommendations were as follows:

  • The condition data provided by the MassDOT Pavement Management Section provided critical data required to be able to evaluate the performance of monitored projects over an extended period of time.
  • The tested alternative technologies and specifications generally provided acceptable performance in terms of rutting, cracking and ride quality. If the projects continue to display acceptable levels of performance over time, it was suggested that final specifications be developed so that that same mixtures and strategies can be used in the future.
  • For future road paving projects involving new technologies, it was recommended that a monitoring plan be developed and implemented before the start of these projects. This would allow for a more comprehensive collection of data regarding the technologies’ performance and cost-benefit results over time and assist MassDOT in making more informed decisions when developing project specifications.

The final study report by Dr. Mogawer and Mr. Austerman can be viewed at this link.  This research was funded through the MassDOT Research Program with Federal Highway Administration (FHWA) State Planning and Research (SPR) funds.

Beets…for Roadway Deicing

by Tracy Zafian, Research Fellow

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beets

Winter in Massachusetts has just recently ended, but already communities are starting to plan and budget for their roadway snow and ice removal next year. Road salt and salt and water mixtures have long been used to help keep roadways clear and safe during the winter. However, there are now some grain and sugar based-options that when combined with salt can be more effective than salt or salt brine alone, and more sustainable as well.

One issue with using salt for road deicing is salt’s corrosive impact on metal, including vehicles and roadway infrastructure. Another concern is the polluting impact that road salt runoff as snow and ice melts can have on waterways, ecosystems, and wells. Through its Salt Remediation Program and commitment to environmental stewardship, MassDOT has established specific initiatives, as the program website says, that is aimed at “promoting the effective and efficient use of deicing chemicals.” One of the initiatives was the creation of the Snow and Ice Materials Usage Committee. This committee is charged with examining Best Management Practices for snow and ice removal, evaluating potential alternative roadway deicing options, and reviewing and revising current deicing policies.

Different Departments of Public Works (DPWs) have tried combining different agricultural materials, such as beet juice, beet molasses, cheese brine, and others, to their road salt to create better deicing mixtures. These agricultural additives contain carbohydrates that work chemically with road salt to lower the freezing point of water. These liquid mixtures can be sprayed on streets in advance of storms, which reduces salt bounce and helps prevent ice from forming. Such mixtures are also less corrosive.

Beet-based deicing mixtures have long been popular in the Midwest. Here’s a 2008 NPR story on the use of beet juice for deicing in Ohio. The DPW in Waukesha, Wisconsin has used a beet juice-salt brine mixture it prepares itself, as has Washington, D.C. Some Massachusetts communities are now using commercially-prepared beet molasses mixtures. As reported in a recent Boston Globe article, Wellesley officials started researching carbohydrate-based deicing additives after hearing great things about their use in other parts of the country. Wellesley Highway Division general foreman Kevin Collins and his team have been happy with the product, Magic-0 (Magic Minus Zero), that they started using in 2017. The product combines sugar cane molasses and magnesium chloride into a liquid mixture. It has been used by many highway departments and state agencies throughout New England, New York, New Jersey, and Pennsylvania.   The town of Lexington, under DPW superintendent Marc Valenti uses something similar. Another popular deicing product made from beet molasses is Beet Heet. Beet Heet has been used by over 200 agencies in 8 states, mainly in the Midwest. The beet molasses products can offer the benefits of beet additives with better consistency and performance than beet juice mixtures. Some cities, such as Milwaukee, discontinued the use of beet juice additive after finding it clogged their truck sprayers.

Other tested deicing additives include cheese brine, which is the water remaining with cheeses such as mozzarella. Cheese brine has been used for deicing in Polk County, Wisconsin, since 2009, and was pilot tested a few years ago in Milwaukee. Pickle brine was pilot tested in New Jersey in 2014. Researchers at Washington State University have developed a deicer made of barley residue from vodka distilleries. With additives made from byproducts of food processing plants, location and access to the processing is a factor, and one reason, for example, that Wisconsin is the main adopter of cheese brine deicing.  For local byproducts, the costs of the additives can sometimes be negligible as processing plants are happy to share their waste products in a win-win situation that can lower their own production costs as well.

As discussed in the Boston Globe, for now, the City of Boston currently primarily uses salt and sometimes a mixture of salt and water. However, the City’s Public Works Deputy Commissioner Michael Brohel says that carbohydrate-based additives could be in the city’s future. “We’re always open to testing out new methods,” says Brohel.

Baystate Roads plans to include discussion of deicing additives in its Snow and Ice Operations training for the next snow season.

Managing Assets at MassDOT

by: Matt Mann, Research Program Coordinator

longfellowpainting
Longfellow Bridge

MassDOT continues to monitor, repair and replace its existing transportation infrastructure.  Bridges are a key component of the infrastructure and essential for Massachusetts growing economy.  Through data collection, bridge inspections, and daily maintenance, MassDOT knows when each bridge will need to be replaced or rehabilitated.

MassDOT performs a regular and semi-regular inspection of their bridge network.   Funding for the bridge infrastructure looks at ownership and length of the structure.  Collecting bridge attributes and deficiencies allows MassDOT to develop comprehensive of their assets.

Over the past few years, the Accelerated Bridge Program (ABP) has met the challenges to reduce the number of deficient bridges in the Commonwealth.  The goal of this Program is to deliver projects quickly and relies on accelerated bridge construction as a means to reduce road closure durations. There are two specific bridge projects that are looking to accommodate demand and technology for the next generation.  One is in the implementation phase and the other in the research phase, both shining a light on MassDOT’s commitment to accommodating future transportation demand in the Commonwealth.

MassDOT is undertaking the Longfellow Bridge Rehabilitation Project, one of five major projects of the Commonwealth’s ABP. This historic bridge provides vital transportation connections between Boston and Cambridge.  Keeping in-line with the historic character of the bridge, structural deficiencies will be addressed, and multi-modal connections will be improved.

A recently launched MassDOT research project looks more closely at the deterioration of the steel beam ends due to corrosion of leaking bridge joints. Dr. Simos Gerasimidis of UMass Amherst is the Principal Investigator on the project. We asked him to give us some information on the project and the expected outcomes.

“As the Commonwealth’s bridge population ages, MassDOT is witnessing more and more instances of deterioration of the web at steel beams ends due to corrosion as a result of leaking bridge joints. This deterioration reduces the load carrying capacity of beams at a critical point where the beam sits on its bearing. In extreme cases, the web fails and the bridge has to be closed. Therefore, the determination of the remaining load carrying capacity is very important, however, there are no good methods for performing this analysis and so, it has been very difficult to calculate realistic estimates of the remaining capacity of the web. This research aims to first; identify the most common configurations (shapes and locations) of steel beam end deterioration by reviewing detailed inspection reports for various bridges. These patterns will be used to develop advanced computational models for structural analysis and the results of the analysis will be utilized to develop new procedures for determining the safe capacity of deteriorated beam ends that can be incorporated into the MassDOT Bridge Manual.

Secondly, actual steel beams with deteriorated ends will be subjected to full-scale testing at the UMass, Amherst Structural Testing Facility to validate the procedures that are being proposed. Finally, the ultimate goal of the project is to update the current guidelines as they appear in today’s codes.”

Both of these bridge projects will benefit the Commonwealth for years to come.  Combining data analysis and maintenance, with innovation and technology, will continue to keep our infrastructure in good shape.

MassDOT at TRB 2018!

by: Matt Mann, Research Program Coordinator

Image result for transportation infrastructure repurposing

Nikki Tishler, Transportation Planner and Title VI Strategist for MassDOT, provided great moderating skills at last week’s Transportation Research Board Annual Conference, as she orchestrated the session: Repurposing and Resizing Our Infrastructure: Responsible Investment for the New World.  The presentations and discussions centered on right-sizing the infrastructure for future transportation function, efficiency and service.  DOT’s continue to improve project and asset management processes as they integrate existing and future societal needs with an anticipated reduction in funding.

Efficiency Needs to Pay the Bills

by Matt Mann, Research Program Coordinator

gastax(2)

Infrastructure maintenance continues to be costly and finding equitable solutions to pay for it will be challenging.  Historically, infrastructure repairs fell on the revenue made from the gas tax.  The gas tax had been a fair way to have all infrastructure users pay their share.  With the purchase of fuel efficient vehicles (eg. Zero emissions vehicles (ZEV) and battery electric vehicles (BEV)) on the rise, especially out west, relaying on trips to the gas pump to fix the highways is not sustainable.

Currently, eight states have passed bills that include a form of assessment on ZEVs and BEVs.  These assessments include an additional registration fee and/or licensing fees.  These two revenue forms do not demand an upstart cost and are easy to implement.  In-terms of other revenue sources (eg. mileage based fees) a couple of states have discussed introducing a bill for this; but the State of Arizona is the only that tried to pass a bill, but it didn’t get any traction.

Even though the sale of vehicles that have zero or reduced emissions is on the rise, putting something in place to track vehicle distance or mileage is still a ways off.  California, who is leading the nation with the number of ZEVs and BEVs, has recently considered developing a mechanism to tax per mile someone who has one of these vehicles.  Ideas that have been discussed include: tracking your mileage every time you pull up to the gas station or charging station; or retro vehicles with a tracker (collecting miles driven).   Tracking miles would require additional funds for operation and administration.

A recent MassDOT published report by UMTC Research Affiliates Song Gao and Michael Plotnikov titled:  Zero Emission Vehicles: Impacts on Transportation Revenue, states that Massachusetts currently pays for their infrastructure maintenance through a state and federal gas tax, vehicle registration fees, and the purchase and use tax.    MA passed a bill earlier this year, promoting electric vehicle use.  There continues to be discussion in MA about other ways users of ZEV and BEV can financially contribute to maintaining the transportation infrastructure.

 

Where is my Snowplow? Snowplow Apps and Cams Comfort Drivers

by Tracy Zafian, UMTC Research Fellow

MNDOT_snowplow_webcam
Minnesota DOT

When snowy weather comes, drivers want to know which roads have been plowed and what the road conditions are.  A number of state Departments of Transportation (DOT) are now providing the public access to the real-time data that the DOTs collect on roads and plows.  Some states even have snowplow dashboard cameras so people can watch the plows at work and see the roads as the plow drivers see them.

The Iowa DOT’s Track a Plow program started in 2013. Track a Plow lets anyone with Internet access see where plows are operating, and view photos taken from cameras attached to plow windshields.  As described on the Iowa DOT web site, “the data and images coming from the snowplow trucks are part of a larger data collection process that includes global positioning satellite and advanced vehicle location technology to help the Iowa DOT make smarter decisions related to treating Iowa’s roadways. Eric Abrams, the Iowa DOT’s geographic information systems (GIS) coordinator, developed the architecture behind the public website. ‘Our snowplow trucks are now equipped to collect a wealth of information. Some of it is more useful to managers and supervisors at the DOT and some of it helps everyone. We’ve made the data available in a variety of layers on the track a plow site so people can pick and choose what they want to see. So far, the camera layer has been the most popular with the public.’”

The Michigan DOT (MDOT) piloted its snowplow tracking program for the past few winters and has now expanded it statewide. The department’s Mi Drive website and app for traffic conditions lets people see where MDOT snowplows are and also whether they are actively plowing or applying ice melting materials. Some of the plows also have webcams which can be viewed through Mi Drive. As the MLive newsite reported, “MDOT has long allowed access to traffic cameras and images, but this new feature will show the havoc of Michigan’s winter with a first-person (vehicle) view.”  Information on the web site and app is updated every 60-90 seconds. According to MDOT, the Mi Drive app version is especially popular with motorists as it is faster and easier to use than the web site and allows more customization.

The Minnesota DOT (MNDOT) pilot tested snowplow cams for the first time last year and put them on about 200 plows (25% of the MNDOT fleet). A short video on this MNDOT initiative can be seen here.  The snowplow info shared with the public by MNDOT is part of the Minnesota’s 511 road information system (511mn.org).

Other state DOTs do not have web cams on their snowplows yet but still share weather and snowplow data online, and give the public access to some of their GIS data layers used by staff. The Pennsylvania DOT shares snowplow locations through its 511pa.com site. The Utah DOT (UDOT) includes a snowplow layer in its real-time UDOT Traffic web site and smartphone app. This website and app gives plow locations and shows where the plows have traveled in the last 30 minutes (the data is updated every 3-5 minutes). Last winter, the Vermont Agency of Transportation (VTrans) launched its Find My Plow site which helps motorists see where plows have been, and when the next plow is coming, so they can plan their driving trips accordingly.

 

Safe Driving Liquid Solutions for Winter Roadway Maintenance

by Matt Mann, Research Program Coordinator

salt-brine

A major goal of winter maintenance is keeping the rods free from ice/snow.  There is pre-storm preparation and then there is maintaining the roads, in safe conditions, during and after a weather event.  The factors that agencies take into consideration when trying to achieve this goal range from available staff, application rates anti-ice and de-ice material, temperature, and impact on fleet etc.  Among the various solutions, generally, salt is used during a weather event, based on its effective de-icing capabilities; also, it’s easy to handle, store and apply.  Some negative qualities of road salt include: its effectiveness decreases dramatically at 15 degrees and less, it is highly corrosive, it does not stay on the road as much, and it can be costly.

Along with road salt, other winter road products include a number of liquid solutions and/or treated salt.  Some liquid solutions and their qualities include:

  • Calcium Chloride (CaCl) – highly corrosive, freezes at -15 degrees
  • Magnesium Chloride (MgCl) – less corrosive (safe around plants/animals), freezes at -20 degrees
  • “Ice Be Gone”/Magic Minus Zero – non-corrosive, freezes at -40 degrees and is EPA approved
  • Caliper M-1000 & 2000 – non-corrosive, freezes at -85 degrees, good for pre-wet

Another alternative for regular road salt is to treat it.  Some options for treated salt are Magic Salt, Fire Road and Clear Lane.   All of these are less corrosive than regular salt.  Also, when salt is treated, up to 90% stays on the road; where-as un-treated salt, only 60% stays on the road.

Most of the liquids mentioned above can also be used on gravel roads as dust control as well; this adds additional stabilization for the road and prevents loss of gravel over the years.  The costs of these liquids solutions range from MgCl being the cheapest to “Ice Be Gone” being the more expensive one.  In the middle is Caliper M-100 and M-2000.

Currently MassDOT pre-treats the state highways with a salt brine, and pre-wets their roads with MgCl.  They are able to get a jump on most weather events by using pavement temperatures sensors and the Roadway Weather Information Stations (RWIS).  Speaking with Paul Brown, District 1, MassDOT, “Most new trucks are equipped with pavement temperature sensors.”  MassDOT also fully utilizes the RWIS, which measure real-time atmospheric parameters, pavement conditions, water level conditions, and visibility.