In August 2001, Road Talk reported on the Ministry of Transportation’s very first purchase of hybrid cars for fleet vehicle use: two Toyota Prius sedans. Since then, the ministry has made considerably greater investments in “greening” its fleet of vehicles. Road Talk provides an update on the ministry’s current green fleet, via the article below, reprinted with permission from Rousseau Automotive Communication, Fleetdigest magazine, December 2009.
For more information, please contact: Shaf Khan, Manager, Fleet Management Office, Ministry of Transportation at (905) 704-2968 or Shaf.Khan@ontario.ca
by Jack Kazmierski
MTO Deputy Minister, Bruce McCuaig shown with the Manager of the Fleet Office, Shaf Khan
Transportation is the largest and fastest-growing producer of greenhouse gas emissions in Ontario -- and passenger vehicles are a major part of the problem.
As the manager of the Fleet Management Centre for the Ministry of Transportation, Shaf Khan is busy putting into practice the government’s commitment to reducing its Green House Gas (GHG) footprint. While each ministry services their own vehicles, Khan and his team provide fleet management services and guidelines for the Ontario Public Service (OPS) fleet consisting of over 10,000 vehicles.
No Magic bullet
Some would say the answer to fuel-efficiency and clean emissions is simple – stop driving gas-guzzling cars and take public transit. But the problem is more complex and the Ministry of Transportation is tackling the emissions problem with a multi-pronged approach.
“Many of the vehicles in the OPS fleet are hybrid, alternative fuel or fuel efficient vehicles” Khan says.
The government is also using E85, a fuel blend containing 85% ethanol in their Flex Fuel Vehicles (FFVs). FFVs can use either E85 or traditional gasoline. Since ethanol stations are difficult to find, the Ministry operates a number of ethanol fueling stations for government vehicles.
Deputy Minister Bruce McCuaig strongly supports the government’s commitment to reducing the emissions of the OPS fleet. “Moving quickly to a greener fleet not only stimulates the economy but it demonstrates environmental leadership,” he said. “I am encouraged by the level of commitment to combat global climate change in people like Shaf Khan and others throughout the OPS.”
Khan and his team also encourage the use of alternative fuels like propane and natural gas. Naturally, hybrids are also part of the mix, and the hybrid fleet seems to be growing exponentially. “Four years ago we had less than 20 hybrids. Now we have well over 640,” Khan says. “That’s going to have a significant impact on the reduction on our emissions.”
The next step in the quest for lower emissions is the electric car. Ontario is leading by example and will green its operations by purchasing, if available, 50 electric vehicles per year between 2011 and 2020 (500 in total). Twenty per cent of eligible new Ontario Public Service passenger vehicle purchases will be electric by 2020. OPS garages and/or parking facilities will be retrofitted to be able to recharge the fleet. “Electric vehicle purchases will contribute to the overall OPS Green Transformation and its goal of trying to reduce fuel consumption by five percent annually,” explains McCuaig. “The purchasing of electric vehicles will not only help the environment, but it will also strengthen the economy by driving innovation, revitalizing the global auto sector and creating jobs.”
It’s clear the Ontario government supports green innovation in the automotive sector. “To get to where we need to go there’s no single solution,” Khan says. “We have to use a combination of strategies to reach our goal of reducing emissions.”
During data collection, trucks towed the Traction Watcher One (TWO) device in the left wheel track. Continuous friction measurements were transferred to a laptop mounted inside the vehicle. The device captured 10 readings per second, which were averaged per second and exported in MS Excel format for visual presentation and data analysis. To assist with data analysis, both tow vehicles were equipped with a digital video camera, GPS, and Automatic Vehicle Location (AVL) capabilities.
The Halliday RT3 Friction Meter is used to model relationships between surface conditions and surface friction during winter storm events.
The hot water sander method is simply based on a mixture of hot water and sand.
Vaisala Friction Sensors
One set of Vaisala sensors was installed on the eastbound lanes of Highway 417 near Casselman, Ontario. The sensors are installed on a pole at the roadside and positioned 8.3 metres over the roadway.
The Maintenance Technology Project (MTP) is the Ministry’s focus for identifying, evaluating, demonstrating, and implementing new technology in highway maintenance. The original objectives have evolved since the project began more than ten years ago, but they still follow the vision of keeping Ontario a highway maintenance leader in effectiveness and efficiency. The Project also supports the ministry’s strategic direction of promoting the use of leading-edge technology, materials and equipment for winter operations on provincial highways and municipal roads, to ensure that maintenance operations use road salt, plows and spreaders effectively in providing safe winter driving conditions.
The MTP project has four strategic goals:
Project goals are accomplished through partnerships between MTO Head Office, Regional Offices, other highway agencies, product manufacturers and vendors, and maintenance contractors.
Several new technologies are under review this year as part of the ministry’s ongoing commitment to the MTP. Most are in early testing stages and will be evaluated further over the 2009-2010 winter season.
Winter performance measures using friction data
In the winter of 2006/07, MTO Head Office and Eastern Region Contracts Office studied the applicability of winter friction testing. Their primary objective was to measure road performance during and after winter events with a quantifiable and objective measure to determine if a consistent correlation could be found between the road surface condition (e.g. bare and wet, snow covered, icy, etc.) and the coefficient of friction. Development of a reliable, repeatable relationship could potentially lead to province-wide adoption of friction-based performance measures for defining bare pavement.
The study included a jurisdictional scan to identify agencies already using winter friction as part of their current maintenance policy. A detailed overview of winter maintenance practices, and specifically the use of winter friction, was provided for Ontario, Norway, and Ohio.
This winter, MTO will be conducting further winter friction testing using three different monitoring devices (two are shown in the photos) in the Ottawa, North Bay, Thunder Bay and Guelph areas to support the development and validation of friction-based performance measures comparable with bare pavement monitoring.
Hot Water Sander
This sanding method is simply based on a mixture of hot water and sand. Water is heated to a temperature of 90ºC to 95ºC and then lightly applied to the sand before being dispersed. Heat causes the sand to embed itself into the ice or snow pack and then freeze in place. Compared to other methods that require frequent re-application to replace sand that is blown off the road by traffic, hot water sanding results in a longer-lasting application. Traffic gradually wears away the top layer, but enough sand remains embedded in the snow or ice to continue to provide friction.
Hot water sanding offers environmental benefits as well. The longer the sand remains in place, the fewer spreading cycles are required, which translates to a reduction in emissions. In addition, hot water sanding does not require the use of salt—unlike dry and pre-wet sanding mixtures, which include 3 to 5% salt by volume. Eliminating salt from the mixture reduces the amount of salt applied to the roads, lowering costs and supporting the ministry’s salt management objectives.
The hot water spreader is ideal for lower volume highways that are maintained in a driveable but snow packed condition for most of the winter. The hot water units have been used on Highway 599 in Northwestern Region and on Highways 603 and 533 in Northeastern Region. Further testing and evaluation is underway to monitor friction levels, material and equipment use and costs.
Directional Salt Spreading
The conventional method of spreading salt on highways is by distributing salt through a chute positioned perpendicular to the truck and aimed at the crown (centre) of the road. As the truck travels, salt is spread down the centre of the road, and as it melts, the brine runs across both sides of the road, clearing both directions at once. Recently, the ministry has been exploring an alternative—directional spreading. Using this method, the chute is positioned to distribute salt underneath the truck so that it is applied only to the lane in which the truck travels. This puts salt on the road more quickly since each lane can be salted as it is plowed, rather than salting only on the return trip after the outbound lane has been plowed.
Testing for directional spreading was conducted in Eastern Region on Highways 34 and 138 during the winter of 2008-2009. Results are currently under review and are expected to be reported in 2010.
Underbody Finger Plow
The ministry is currently evaluating an off-the-shelf product—a plow that features flat tines that move independently of one another, allowing the sectional moldboard to reach deep into wheel ruts and uneven surfaces. Manufactured by Viking-Cives, the Underbody Finger plow is designed to remove more snow mechanically and minimize wheel tracking (ruts), resulting in less chemical required to obtain a bare and safe driving surface. Viking-Cives is providing all of the equipment, including the truck, at no cost to the ministry.
Testing is scheduled to be conducted in January 2010 on Class 4 highways near Kapuskasing, Ontario.
Highway Frost Forecast Map
The Ministry’s Road Weather Information System (RWIS) provides weather and road condition observations and forecasts at approximately 120 monitoring sites across the highway network. These include temperature, humidity and salinity information that is used by road maintainers to plan and schedule plowing and salting operations during winter storms.
Road-weather conditions vary along the tens to hundreds of kilometres between monitoring sites and this requires patrol staff to make educated guesses about the intervening conditions to plan operations that are suitable for an entire route. Lack of information about intervening conditions—especially where variations in temperature and relative humidity result in unobserved frost or black ice—increases the risk of slippery road conditions.
Recent advances to instrumentation on maintenance patrol vehicles including GPS, infrared thermometers, and mobile dew point sensors, provide detailed information about some of the factors that control winter road conditions between RWIS sites. These can be used to develop fingerprints of temperature and dew point conditions to provide a forecast of variations in the potential for frost or black ice along a maintenance route.
A study is under development to determine the benefits of utilizing thermal mapping—the process of using vehicle-mounted thermometers to measure temperature variations along the highway—to determine when and where cold temperatures occur. This would assist in forecasting when icing will occur on cold, clear nights in a particular location, and in developing a directed response to those conditions.
Vaisala Friction Sensors
MTO has been investigating two new remote optical pavement sensors for monitoring road surface conditions, as compared to traditional in-situ pavement sensors and visual observations:
One set of the Vaisala sensors was installed on Highway 417 about 56 km east of Ottawa, near Casselman, Ontario. Data collected by the Vaisala sensors was compared to data collected in the same location by a traditional in-situ pavement sensor approximately one metre away. Initial testing showed excellent correspondence between temperatures monitored by this device and a conventional, in-pavement temperature sensor. Grip levels did not correspond as well and additional work is planned for this winter to learn why there were differences.
MTO Maintenance Open House
Each spring, new, state-of-the-art winter maintenance technologies are showcased at the MTO Maintenance Open House. This well-attended and anticipated event is an opportunity for ministry staff, contractors, vendors, and industry partners to observe and discuss new winter maintenance equipment and to find out how winter maintenance operations may be changing in Ontario. This year, MTO will be hosting its Open House in late February 2010.
The success of the Maintenance Technology Project is best demonstrated by the innovations that are now implemented across the province. All of the following projects were originally tested and/or evaluated through the MTP initiative.
Road Weather Information Systems (RWIS)- The first RWIS installations began in 1988. In 1996-1997, the ministry evaluated pavement and roadside sensors and by 2001, the systems were fully implemented. Today, there are 115 sites across the province. Benefits include: better atmospheric and pavement forecasting and informed operational response (right action, right time, right amount).
Anti-icing/De-icing -Testing and evaluation began in 1996-1997 with full implementation in 2002, including development of variable salt application rates and evaluation of pre-treated salt. Benefits include: reduced salt usage (up to 11%, with local variations), better salt retention, and proactive snow and ice response.
Infrared thermometers -The technology was evaluated and implemented province-wide in 1998-1999. Benefits include: improved monitoring and response to winter storms and improved operations.
Friction trailers - MTO has evaluated the technology/devices, which are now in use for data collection on other MTP projects. Benefits include: practical evaluations of new technology/devices through MTP and development of performance based standards.
Flexible plow blades - Improvements in blade technology have resulted in improved snow removal, and reduced salt and sand use.
Automated Vehicle Location (AVL) -The ministry has implemented AVL systems and road patrol diaries. Benefits include: improvements in patrolling operations and winter storm response, real-time monitoring and decision making.
Fixed-Automated Spray Technology (FAST) - These systems have been implemented at eight MTO sites to improve anti-icing for bridges. Benefits include: proactive automated anti-icing strategies at bridge decks and reduced salt use.
Pre-wet salt -Use of this material has been tested in Huntsville, Ontario, and is now accepted for use, resulting in more effective salt use.
Tow Plow -MTO has evaluated the trailer plow, which has led to improvements in snow removal. The tow plow is now permitted for use in Ontario and is currently in use on an AMC contract (York) and 407 ETR.
For more information, contact Steve Birmingham, Maintenance Standards Section, Highway Standards Branch, at firstname.lastname@example.org or (905) 704-2852.
Aerial view of a roundabout with 4 intersections
Roundabouts are relatively new to Ontario’s provincial highways and many drivers are unfamiliar with their roadway geometry and physical features. With the completion of the first roundabout on Highway 33, just west of Picton, the Ministry of Transportation (MTO) is finalizing its policies for roundabout features intended to aid road users as they get used to this type of intersection.
The most recent policy establishes warrants and design guidelines for roundabout lighting. Darkness can add challenges to navigating a roundabout and identifying vehicles, cyclists, pedestrians and features within it. Lighting is particularly helpful given the geometry of a roundabout requires drivers look to the left of their vehicle outside of the area where their headlights are pointed,. Lighting increases a driver’s visibility and is consistent with Canadian and North American roundabout standards.
During a rainstorm, pollutants from tire wear, engine oil leaks, break pad wear, metal rust, car fumes and atmospheric deposition which have settled onto pavement surfaces combine with stormwater runoff reducing its quality. Compared to natural areas, runoff from impervious roads has increased pollutant loads that can be harmful to birds, humans, plants and aquatic life.
A policy for signing and pavement markings at single-lane roundabouts has also been developed. It includes typical layouts showing guide, regulatory, and warning signs, their location and relative dimensions, as well as pavement marking layouts. The sign designs and layouts were developed in cooperation with the Ontario Traffic Conference and through discussions with several municipalities that have already built a number of single and multilane roundabouts.
MTO also continues its development of a signing plan for multi-lane roundabouts and is a member of the Transportation Association of Canada (TAC) steering committee that is also working on this project. The final TAC report will be presented to the Traffic Operations and Management Standing Committee for approval in the spring of 2010. MTO anticipates adopting the recommended signs and markings as presented in the report and expects that signing will be similar to single-lane roundabouts with the addition of lane designation signs and pavement markings for multiple lanes. MTO also anticipates TAC recommendations for overhead signing, which currently varies throughout North America.
The new roundabout illumination and single-lane signing/pavement marking policies are effective immediately and can be found on the ministry’s Traffic Office site. These policies will be available on MTO’s public website in the near future.
Roundabout Documents available to the Public:
Highway 33 Roundabouthttp://www.mto.gov.on.ca/english/engineering/roundabout/index.shtml
Highway 33 / County Road 1 - Roundabout A User Guidehttp://www.mto.gov.on.ca/english/engineering/roundabout/round-about-brochure.pdf
MTO Intranet (For staff only)
Traffic Office - Policies/Guidelines
Roundabout Lighting Policy Finalhttp://portal.mto.ad.gov.on.ca/sites/MTO/PHM/HSB/Traffic/Policies/Roundabout Lighting Policy Final.pdf
There are many existing urban stormwater management technologies which stabilize and filter out contaminants, but often these do not meet the provincial water quality guidelines. With proper design, compost biofilters, when used alone, or in combination with other stormwater management systems, are a cost effective treatment that will continue to improve runoff water quality.
Box girder showing shear studs on the inside of the bottom flange.
Installing the Heart Lake Road Underpass semi-continuous box girders, span by span.
A new underpass opened in Brampton in July, 2009, and is the first bridge of its kind built by the Ministry of Transportation (MTO). The Heart Lake Road Underpass is a semi-continuous steel box girder bridge constructed as part of the recent northern extension of Highway 410.
In preliminary design, the Heart Lake Road Underpass was a three span, pre-cast, pre-stressed, concrete (CPCI) girder bridge, with spans of 23.5m, 17.5m and 31.8m; with the third span accommodating the Mayfield Road off-ramp. The bridge was also designed with fully-integral joints replacing traditional deck expansion joints. (See the inset explaining multi-span deck expansion joints.) By the start of detailed design, the bridge was adjusted to a two-span steel box girder design with spans of 41.0m and 31.8m.
However, during detailed design, the off-ramp to Mayfield Road was realigned, resulting in reduced span lengths of 32 m each. For these spans, a box girder superstructure became uneconomical and could not be justified compared to other alternatives.
Rather than a complete redesign as a CPCI superstructure, regional structural engineers proposed modifying the design from a steel box girder to semi-continuous design. While new to MTO, US DOTs have experienced some cost savings with semi-continuous designs over conventional steel girder construction because:
Together with industry partners, MTO has developed a uniform set of principles that will guide specification development in each material area. These principles are:
In contrast, a semi-continuous steel girder avoids most of these costs and only requires a little more positive (midspan) moment capacity. Since the box girders have a wide bottom flange, the expense is minimal. The cast-in-place concrete diaphragm provides continuity for superimposed live load.
In an attempt to further reduce structural steel fabrication costs, the steel stiffeners for the box girder bottom flanges that are typically hand-welded were replaced with a 150 mm thick cast-in-place concrete fill which was secured to the inside of the bottom flange with shear studs.
Ultimately, the Highway 410-Heart Lake Road Underpass was constructed as a two-span, semi-continuous steel box girder bridge with cast-in-place concrete deck and integral pier diaphragm. The deck cross-section carries two lanes of traffic on Heart Lake Road yet the substructure has capacity for four. The bridge has been constructed with atmospheric corrosion resistant (or weathering) steel.
Due to the success of this new design, the Ministry has an alternative to the typical CPCI girder bridges, particularly where transportation of the long span girders (greater than 45m) can be problematic.
In addition, the semi-continuous steel box design has potential to be part of a rapid bridge construction project. By placing the concrete deck on one or more boxes in a staging area; the entire assembly could be lifted into position, followed by cast-in-place concrete for the longitudinal closure strips between assemblies, and the end diaphragms at the piers.
Typically, the superstructure of a multi-span bridge is designed as a series of simply supported spans with an intermediate deck expansion joint over each pier; in effect, a series of single span bridges placed end to end. This approach is easy to construct and easy to design, as load effects in any one span are independent of loading in adjacent spans.
However, intermediate deck expansion joints tend to lead to increased roadway maintenance costs as well as shorter bridge rehabilitation cycles as bridge components prematurely deteriorate when exposed to leakage through their expansion joints.
Typically, steel I-girder bridges are fully-continuous spans – the girders are installed as a single element from abutment to abutment, usually by field splicing shorter girder elements together, prior to placing the concrete deck. Typically, CPCI girder bridges are semi-continuous spans – the girders are installed as individual elements span by span, similar to a simply supported bridge, but with concrete diaphragms placed monolithically with the concrete deck at the piers connecting the ends of the girders together.
For more information, please contact Randy Yu, Area Engineer Structural, at (416) 235-5511 or at Randy.Yu@ontario.ca
Comparison of salt application settings for dry salt, pre-wet using conventional spreader and pre-wet using salt management spreader
Rexroth CS-440 controller unit.
A typical spreader truck used at the Sportsworld patrol yard.
Road salt is a critical component of the Ministry’s tool-box for keeping roads safe and traffic flowing during winter storms. MTO is committed to use as little road salt as necessary while maintaining road safety – a delicate balance. This balance also supports Environment Canada’s Code of Practice for the Environmental Management of Road Salts under the Canadian Environmental Protection Act. In support of the Code of Practice, MTO continues to evaluate and test new technologies, methods and products that have the potential to reduce salt use. Recently, the ministry completed a two-year study of automated salt management spreaders to evaluate their potential.
The effectiveness of salt varies with temperature, and surface temperature of the road varies due to pavement characteristics, underlying soil properties, shading and other factors. Automatic spreaders have typically adjusted the quantity of material placed on the road based on the speed of the vehicle, but this technology, proposed by Steed and Evans, an Area Maintenance Contractor in Cambridge, Ontario, automatically adjusts salt spreading rates according to road surface temperature variations. It was expected that the overall quantity of salt could be reduced.
With conventional spreading technology, the target spreading rate is set and seldom adjusted along the route. Many conventional spreaders are limited to only a few application rate settings and therefore follow guidelines with a total of five salting rates over the range of temperature and snowfall conditions. This is illustrated by the blue line on the graph below, where relatively large adjustments occur at temperatures of -5 and -10˚C. The test salt management spreader is capable of more increments. It was programmed to have the same target rate as the conventional spreader and to increase or decrease the rate in steps of 9% with a surface temperature change of at least 3˚C, illustrated by the red line in the graph. The more frequent, smaller increments of the salt management spreader were expected to reduce the total amount of salt applied.
Steed and Evans set up the evaluation on their Highway 401 route near Kitchener with a conventional spreader operating in one direction and a modified test spreader operating in the opposite direction. Each route was approximately 20 km long. The conventional spreader was equipped with a Compu-Spread 440 /Bosch Rexroth electronic spreader control (ESC) unit. As well as ensuring that the road salt is spread at a constant rate irrespective of how fast the truck is moving, the ESC unit provides information on application rates and other data including date, time, ground speed, latitude and longitude coordinates, pre-wet application rate and type of material being used. The operator electronically sets the salt application target rates using pavement and air temperature readings from the Road Weather Information System sensors in the area before setting out.
The spreader controller on the test truck was upgraded with four innovative components:
Each time the spreader went out, the ESC tracked changes in road surface temperature and salt application rate on the test unit.
Data was collected by the spreader controller and the on-board thermometer, during numerous runs over the two-year test, to answer three questions.
The surface temperature variation along the test route was relatively small during the test storms, and rarely exceeded the 3o C criteria to change the salt rate during a single run.
This may be due to snow cover during a storm providing a colder/non variable surface temperature or the highly uniform construction of the freeway section that minimizes road temperature variations (a lower volume, 2-lane highway may be subject to more variation in construction materials, topography or shading that results in more frequent and larger temperature differences).
The modified spreader took about 40 seconds or 450 metres along the road to reach the set application rate beginning from a stop, and about 15 seconds or 180 metres along the road to adjust to a new rate with a shift in road temperature. These results were better than expected based on conventional technology, and are important because the changes in application rate must keep pace with changes in road temperate as the truck travels along the road at 40 km per hour or more. By comparison, temperature changes of more than 3 degrees C and sufficient to trigger a change in salt spreading rate, occurred on average every 2.4 km.
Conventional spreader application rates fluctuate continuously as the control system adjusts to varying road speed. It was found that the modified spreader maintained an application rate within 1% of the set rate when road temperature is constant. This is considered to be very accurate for a spreader control system.
To analyze the average application rate used by each truck on a given day, the total amount of salt spread on the road (kg) was divided by the total number of kilometres travelled. In most cases, the average application rates for both trucks were relatively similar. The automated spreader management test truck used less salt than the conventional truck on only three out of fifteen qualified test days. Further, when the average application rate for each truck is calculated, the test truck used on average 5% more salt than the control truck. While the salt application rate settings were analysed, the total number of salt applications in each storm and the resulting road conditions were not compared between the conventional and salt management test spreader routes. Therefore the overall savings in road salt cannot be directly estimated from these tests. Patrollers observed that generally, more applications were needed in the conventional spreader area. It can be concluded only that the salt management spreader made relatively little difference to the overall salt application in this test area.
While salt savings were not achieved, the test provided a better understanding of the technology and its potential for other locations. On the positive side, it demonstrated that conventional spreading equipment can be equipped to adjust application rates very accurately, automatically and on-the-fly, in response to changes in road surface temperatures.
It is expected that use of the technology in a hilly area with pockets of shade or on a lower volume highway could produce more significant results.
Finally, temperature differences along the road may have been damped when snow cover was present on the surface, reducing the overall effectiveness of the technology in reducing salt. An alternative source of road temperature measurements such as predictions based on thermal mapping from a nearby RWIS sensor may result in more dramatic savings.
MTO and its contractors continue to test new innovations in an effort to improve an already exceptional “toolbox” of snow and ice control technologies. Continued research supports MTO’s salt management plan and reduces the use of salt on Ontario’s highways.
For more information, please contact:
Max Perchanok, Research Coordinator, Maintenance Standards Section, Design and Contracts Standards Office, at (416) 235-4680 or atMax.Perchanok@ontario.ca
Heather McClintock, Head-Maintenance Standards Section, Design and Contracts Standards Office, at (905) 704-2964 or atHeather.McClintock@ontario.ca
Two examples of long life pavements - Concrete Pavement on Hwy 402 and Perpetual Pavement on Hwy 406.
As a leader in North America for innovative pavement technology, MTO has a strong history spanning more than 20 years of research, development and implementation of “green” initiatives. Several successful initiatives that demonstrate the ministry’s move toward greener pavements include warm mix asphalt, pervious concrete and asphalt pavements, quiet pavements, full depth precast concrete slab replacements, in-place pavement recycling, and others. Now, MTO has developed GreenPave, a green rating system for pavements that will provide a way of recognizing sustainability in pavement projects.
Using a simple, points based rating system, GreenPave is designed to assess the “greenness” of flexible and rigid pavement designs and their construction. Assigning a rating to pavement design will enable the ministry to incorporate more sustainable technologies in pavements and encourage industry to do the same. For constructed pavements, assigning a rating eliminates design assumptions and allows for incorporation of construction components and contractor innovation that cannot be estimated at the time of design.
The overall concept of GreenPave is based on the LEED certification program for buildings. The University of Washington’s Greenroads system, the New York State DOT GreenLites Project Design Certification Program and Alberta’s Green Guide for Roads also influenced the development of GreenPave. In the proposed rating system, pavements will be assessed within four categories (Table 1).
|Pavement Design Technologies||To optimize sustainable designs. These include long life pavements, permeable pavements, noise mitigating pavements, and pavements that minimize the heat island effect.||9|
|Materials & Resources||To optimize the usage/reusage of recycled materials and to minimize material transportation distances.||14|
|Energy & Atmosphere||To minimize energy consumption and GHG emissions.||9|
|Innovation & Design Process||To recognize innovation and exemplary efforts made to foster sustainable pavement designs.||4|
Each category is further broken down to address specific objectives, with corresponding points assigned to each subcategory. For example, Pavement Design Technologies is divided into four subcategories:
|PAVEMENT DESIGN TECHNOLOGIES|
|PT-1: Long-life Pavement||4|
|PT-2: Permeable Pavements||1|
|PT-3: Noise Mitigation||2|
|PT-4: Cool Pavements||2|
|Maximum Points Available||9|
Specific objectives within these subcategories must be met in order to achieve the maximum points available. For example, under Long-life Pavement, the objective is “to recognize long-life pavements which will help to reduce future rehabilitation requirements and traffic disruptions”. Four points will be assigned when rigid pavements or perpetual asphalt pavements are used.
Proposed rating levels for GreenPave projects are bronze (7-10 points), silver (11-14 points), gold (15-19 points), and trillium (20+ points). Detailed information about the rating categories and points is available on the MTO intranet under the Innovations button or by contacting the ministry’s Pavements and Foundations Section (see below).
Recommended options have been developed for the use of GreenPave at the stages of design and construction:
The GreenPave rating system has been developed and beta tested by Engineering Development Program (EDP) interns and staff in the Pavements and Foundations Section of the Materials Engineering and Research Office. Currently it is being fine-tuned, including consultation with regional Geotechnical sections and industry partners such as the Ontario Hot Mix Producers Association (OHMPA) and the Ready Mixed Concrete Association of Ontario (RMCAO). It is expected to be implemented this year.
Through initiatives such as GreenPave, the Ministry of Transportation remains committed to enhancing the sustainability of Ontario’s transportation infrastructure, including safe, efficient, economic, environmentally friendly technologies and materials that meet the needs of present-day users without compromising those of future generations.
For more information, contact Becca Lane, Head, Pavements and Foundations Section, Highway Standards Branch, at 416-235-3732 or email@example.com.
Send us any ideas, comments, or suggestions concerning local innovations, workshops, or seminars that you would like to see included in future issues.