Municipalities and contractors in Canada and other parts of the world rely on road surface condition information during and after a snow storm to optimize maintenance operations and planning. With an ever increasing demand for safer and more sustainable road network there is an ever increasing demand for more reliable, accurate and up-to-date road surface condition information while working with the limited available resources. Such high dependence on road condition information is driving more and more attention towards analyzing the reliability of current technology as well as developing new and more innovative methods for monitoring road surface condition. This research provides an overview of the various road condition monitoring technologies in use today. A new machine vision based mobile road surface condition monitoring system is proposed which has the potential to produce high spatial and temporal coverage. The proposed approach uses multiple models calibrated according to local pavement color and environmental conditions potentially providing better accuracy compared to a single model for all conditions. Once fully developed, this system could potentially provide intermediate data between the more reliable xed monitoring stations, enabling the authorities with a wider coverage without a heavy extra cost. The up to date information could be used to better plan maintenance strategies and thus minimizing salt use and maintenance costs.

Municipalities and contractors in Canada and other parts of the world rely on road surface condition information during and after a snow storm to optimize maintenance operations and planning. With an ever increasing demand for safer and more sustainable road network there is an ever increasing demand for more reliable, accurate and up-to-date road surface condition information while working with the limited available resources. Such high dependence on road condition information is driving more and more attention towards analyzing the reliability of current technology as well as developing new and more innovative methods for monitoring road surface condition. This research provides an overview of the various road condition monitoring technologies in use today. A new machine vision based mobile road surface condition monitoring system is proposed which has the potential to produce high spatial and temporal coverage. The proposed approach uses multiple models calibrated according to local pavement color and environmental conditions potentially providing better accuracy compared to a single model for all conditions. Once fully developed, this system could potentially provide intermediate data between the more reliable xed monitoring stations, enabling the authorities with a wider coverage without a heavy extra cost. The up to date information could be used to better plan maintenance strategies and thus minimizing salt use and maintenance costs.

No description available.

Since ancient times, roads have tied people and cultures together. Roads have been createdwith the aim of facilitating trade and cultural exchange among different regions in the world. After the technologic development in vehicle industry and dramatically increase of motoring in the world during the past century road communication has gained a great importance for transporting people and goods. Thus, good safety and accessibility on roads all year round is now a vital necessity for a healthy economy in all modern societies. In order to keep roads safe, available for use with high transport quality they need to be maintained in real time. One of the most difficult tasks in this context is to keep the roads in good condition and accessible even during winter. The main objective of this doctoral thesis is to attempt to specify the most efficient ways of executing winter road maintenance.  The preliminary issue in this context is whether it is the use of current assistive tools, that is, technical aspects that should be optimized and developed or whether it is the way in which winter maintenance services are procured and outsourced, that is, contractual aspects that should be improved which could give the optimal impact for both clients and contractors and make winter road maintenance more effective, or both issues. In order to define the outline of the research project a comprehensive state of the art survey was initiated with the intention of collecting and gaining insights into the earlier studies in the research area. Three basic areas associated with the performance of winter road maintenance were considered to be most relevant for review due to the anchorage between the areas. The selected areas were climatological, technical and contractual aspects. The literature review was followed by an electronic questionnaire survey. The results of the study in this stage showed that current technical methods almost functioned in a reasonable manner but there was an imprecise dissatisfaction with the current maintenance contract. The second stage of the research consisted of a number of additional empirical investigations in order to identify contractual problematic issues behind the current winter road maintenance in Sweden. Generally, those factors that are rarely considered as potential underlying causes to costly performance of winter road maintenance in Sweden were studied in this research project for example improper use of related technical assistive tools, procurement of improper bundled winter services and inappropriate contract structure. This thesis consists of six papers, five of which are related to each other, and the first one is completely independent but within research area. Findings in the thesis contributes to extend understanding about; how designing appropriate contracts can improve winter road maintenance, how proper use of assistive tools can reduce unnecessary winter road maintenance costs and minimize road traffic disruptions and delays, how a partnering structure in contracts can create confidence and trust between clients and contractors that in turn leads to minimizing or eliminating conflicts and disputes between parties involved, how choice of appropriate procurement methods through proper bundling of winter road services can contribute to shorten the procurement process and create incentives for contractors, and how selection of proper payment mechanisms can contribute to higher service quality of performed winter road measures. Additionally, an adequate knowledge and understanding of climate, proper knowledge of road weather and its impact on winter road traffic is essential for contribution of better planning of how to maintain the road network during winter. Since understanding about winter issues and its effect on winter road traffic is far from complete and winter road maintenance in the cold regions is a similar challenge, broad and complex, the results of this research may even contribute to improving winter maintenance problems in the countries with severe winters like Sweden. / <p>QC 20140227</p>

Increasing cycling as a means of personal travel couldgenerate environmental benefits if associated with acorresponding decrease in car-based transport. In seeking topromote cycling in wintertime, it is desirable to understandhow important the road surface condition is compared to otherfactors in people's decision to cycle or not. In this thesis,the possibility of increasing the number of cyclists byimproving the winter maintenance servicelevel on cycleways isexamined. The attitudes towards cycling during winter ingeneral, and in relation to winter maintenance of cycleways inparticular, is studied through questionnaire surveys. Bicyclemeasurements are related to weather data from Road WeatherInformation System, in order to know the influence on cycleflow during winter from different weather factors. Fieldstudies are performed testing unconventional winter maintenancemethods, in order to see if a higher service level could beachieved on cycleways and if that would lead to an increase inwinter cycling frequency. The field studies are evaluatedthrough road condition observations, measurements of friction,bicycle counts, a questionnaire survey and interviews. A visualmethod to assess winter road conditions on cycleways isdeveloped, in order to compare the service levels achievedusing different winter maintenance methods. There is a clear difference in mode choice between seasons.With improved winter maintenance service level it could bepossible to increase the number of bicycle trips to work duringwinter with, at the most, 18 %, and decrease the number of cartrips with 6 %. However, it could not be concluded with bicyclemeasurements, that an enhanced service level in fact, generateda higher winter cycling frequency. To increase cycling during winter, snow clearance is themost important maintenance measure. Skid control is not assignificant for the choice of mode but is important to attendto for safety reasons. Winter road condition propertiesimportant both with regard to safety and accessibility ofcyclists, are icy tracks formed when wet snow freezes, snowdepths greater than about 3 cm of loose snow or slush,unevenness in a snow covered surface, loose grit on a baresurface. Weather factors with negative influence on winter cyclingfrequency, are temperatures below +5 ° C,precipitationand strong winds. Only the occurrence of precipitation, not theamount of rain or snow, is significant for the cycle flow. Lowtemperatures are more important in reducing the cycle flow thanprecipitation. Temperatures around 0 ° C seem to be extracritical for cyclists, probably due to the larger influence ofprecipitation and slippery road conditions at thesetemperatures. An unconventional method using a power broom for snowclearance and brine or pre-wetted salt for de-icing, provides ahigher service level than winter maintenance methodstraditionally used, but it is about 2 to 3 times moreexpensive. The method has great potential in regions, such assouthern Sweden, with low snow accumulations but with major iceformation problems. To assess the maintenance service level,the visual assessment method developed and tested in thisproject is adequate for the purpose, however, furtherimprovements are desirable. As a complement to the visualassessment, a Portable Friction Tester can be used to measurethe surface friction on cycleways during wintertime. Keywords:Cycleways, winter maintenance, maintenanceservice level, mode choice, winter cycling frequency, wintermaintenance equipment, winter road condition assessment,bicycle measurements, friction measurement.

<p>Increasing cycling as a means of personal travel couldgenerate environmental benefits if associated with acorresponding decrease in car-based transport. In seeking topromote cycling in wintertime, it is desirable to understandhow important the road surface condition is compared to otherfactors in people's decision to cycle or not. In this thesis,the possibility of increasing the number of cyclists byimproving the winter maintenance servicelevel on cycleways isexamined. The attitudes towards cycling during winter ingeneral, and in relation to winter maintenance of cycleways inparticular, is studied through questionnaire surveys. Bicyclemeasurements are related to weather data from Road WeatherInformation System, in order to know the influence on cycleflow during winter from different weather factors. Fieldstudies are performed testing unconventional winter maintenancemethods, in order to see if a higher service level could beachieved on cycleways and if that would lead to an increase inwinter cycling frequency. The field studies are evaluatedthrough road condition observations, measurements of friction,bicycle counts, a questionnaire survey and interviews. A visualmethod to assess winter road conditions on cycleways isdeveloped, in order to compare the service levels achievedusing different winter maintenance methods.</p><p>There is a clear difference in mode choice between seasons.With improved winter maintenance service level it could bepossible to increase the number of bicycle trips to work duringwinter with, at the most, 18 %, and decrease the number of cartrips with 6 %. However, it could not be concluded with bicyclemeasurements, that an enhanced service level in fact, generateda higher winter cycling frequency.</p><p>To increase cycling during winter, snow clearance is themost important maintenance measure. Skid control is not assignificant for the choice of mode but is important to attendto for safety reasons. Winter road condition propertiesimportant both with regard to safety and accessibility ofcyclists, are icy tracks formed when wet snow freezes, snowdepths greater than about 3 cm of loose snow or slush,unevenness in a snow covered surface, loose grit on a baresurface.</p><p>Weather factors with negative influence on winter cyclingfrequency, are temperatures below +5 ° C,precipitationand strong winds. Only the occurrence of precipitation, not theamount of rain or snow, is significant for the cycle flow. Lowtemperatures are more important in reducing the cycle flow thanprecipitation. Temperatures around 0 ° C seem to be extracritical for cyclists, probably due to the larger influence ofprecipitation and slippery road conditions at thesetemperatures.</p><p>An unconventional method using a power broom for snowclearance and brine or pre-wetted salt for de-icing, provides ahigher service level than winter maintenance methodstraditionally used, but it is about 2 to 3 times moreexpensive. The method has great potential in regions, such assouthern Sweden, with low snow accumulations but with major iceformation problems. To assess the maintenance service level,the visual assessment method developed and tested in thisproject is adequate for the purpose, however, furtherimprovements are desirable. As a complement to the visualassessment, a Portable Friction Tester can be used to measurethe surface friction on cycleways during wintertime.</p><p><b>Keywords:</b>Cycleways, winter maintenance, maintenanceservice level, mode choice, winter cycling frequency, wintermaintenance equipment, winter road condition assessment,bicycle measurements, friction measurement.</p>

Transportation networks play a significant role in the economy of Canadians during winter seasons; thus, maintaining a safe and economic flow of traffic on Canadian roads is crucial. Winter contaminants such as freezing rain, snow, and ice cause reduced friction between vehicle tires and pavement and thus increased accident-risk and decreased road capacity. The formation of ice and frost caused by snowfall and wind chill makes driving a very difficult task. Pavement surface temperature is an important indicator for road authorities when they are deciding the optimal time to apply anti-icer/deicer chemicals and when estimating their effect and the optimal amounts to apply. By forecasting pavement temperature, maintenance crews can figure out road surface conditions ahead of time and start their operations in a timely manner, thereby reducing salt use and increasing the safety and security of road users by eliminating accidents caused by slipperiness. This research investigates the feasibility of applying simple statistical models for forecasting road surface temperatures at locations where RWIS data are available. Two commonly used modeling techniques were considered: time-series analysis and artificial neural networks (ANN). A data set from an RWIS station is used for model calibration and validation. The analysis indicates that multi-variable SARIMA is the most competitive technique and has the lowest number of forecasting errors.

Transportation networks play a significant role in the economy of Canadians during winter seasons; thus, maintaining a safe and economic flow of traffic on Canadian roads is crucial. Winter contaminants such as freezing rain, snow, and ice cause reduced friction between vehicle tires and pavement and thus increased accident-risk and decreased road capacity. The formation of ice and frost caused by snowfall and wind chill makes driving a very difficult task. Pavement surface temperature is an important indicator for road authorities when they are deciding the optimal time to apply anti-icer/deicer chemicals and when estimating their effect and the optimal amounts to apply. By forecasting pavement temperature, maintenance crews can figure out road surface conditions ahead of time and start their operations in a timely manner, thereby reducing salt use and increasing the safety and security of road users by eliminating accidents caused by slipperiness. This research investigates the feasibility of applying simple statistical models for forecasting road surface temperatures at locations where RWIS data are available. Two commonly used modeling techniques were considered: time-series analysis and artificial neural networks (ANN). A data set from an RWIS station is used for model calibration and validation. The analysis indicates that multi-variable SARIMA is the most competitive technique and has the lowest number of forecasting errors.

Several past studies have attempted to quantify the impact of winter weather conditions on highway mobility in terms of traffic volume, speed, and capacity. While consistent in their general findings, these studies have shown considerably different results in terms of effect size and contributing factors. More importantly, most of these studies have not attempted to model the effects of winter maintenance operations on mobility or isolate these effects from those due to snowstorm characteristics, rendering their results and the proposed methods of limited use for estimating the benefits of maintenance activities. This research attempts to address this gap through a statistical analysis of a data set that is unique in terms of spatial and temporal coverage and data completeness. The data set includes both event based and hourly observations of road weather and surface conditions, maintenance operations, traffic volume and speed, as well as several other measures, from 21 highway sections across the province of Ontario. Event based information is available for six winter seasons (2000 to 2006) at 19 of the sites. For this event based data a matched pair technique was employed to determine the changes in traffic volumes and speeds under matched conditions with and without snow events. A regression analysis was subsequently performed to relate the changes in traffic volume and speed over an event to changes in various contributing factors such as highway type, snow event characteristics and road surface conditions. A case study was conducted to illustrate the application of the developed models for quantifying the mobility impact of road surface condition and the mobility benefit of winter maintenance operations. Complete hourly records were available for all 21 sites for three winter seasons. This was used to perform the evaluation on an hourly basis. A matching technique is employed to assign hour-by-hour median speeds observed under typical weather and road surface conditions to each hour of a snowstorm event. A regression analysis is subsequently performed to relate changes from average hourly speed to various contributing factors such as highway type, weather conditions and maintenance operations. Effects of maintenance operations are represented by an intermediate variable called road surface condition index (RSI). A case study is conducted to illustrate the application of the developed models for quantifying the mobility impact of winter snowstorms and the mobility benefit of maintenance operations. The models developed in these analyses confirmed the relationships between weather variables and traffic volume and speed described in the literature. In addition a strong association between road surface condition and traffic volumes and speed was identified.

The objectives of this research were to 1) compile winter maintenance data for the Utah Department of Transportation (UDOT) to directly compare concrete and asphalt pavements with regards to deicer usage and 2) determine if there is a statistical difference in deicer usage on concrete and asphalt pavements. To this end, three data sources were consulted for this research: Material Maintenance Quality Assurance (MMQA) database, UDOT road database, and Google Maps. The final compiled data set prepared for analysis in this research contained deicer quantities by deicer type, pavement surface areas by pavement material type, traffic, longitude, latitude, and elevation data. The deicer data evaluated in this analysis represented the total quantities of each deicer distributed during the 8-year period during which the MMQA database was used by UDOT.Several multiple linear regression analyses were performed to determine if concrete or asphalt pavements required different amounts of deicers, including salt, Redmond salt, brine, wetted salt, magnesium chloride, sand, pre-mix, and wetted pre-mix, during the winter seasons evaluated in this research. Because plow routes were not equal in total pavement area, a variable called “concrete proportion” was created. Similarly, traffic and deicer quantities were divided by total pavement area in lane miles to account for the variation in maintenance station sizes and to allow for direct comparison of the various maintenance stations. After the values of the independent variables were finalized, full and reduced models were created for the total amount of all deicers per lane mile and the amounts of each of the eight individual deicers per lane mile based on the statistical significance of the respective independent variables. A total of 18 regression models were completed for this research.From the results of the statistical analyses, concrete proportion was statistically significant in models for three of the dependent variables, including brine, wetted salt, and wetted pre-mix. However, neither the full nor the reduced regression model prepared for the sum of all deicers had concrete proportion as one of the significant variables. The absence of concrete proportion as an independent variable in these models shows that, on average, after correcting for differences in traffic volume and pavement area, deicer usage in Utah is not affected by pavement type. Therefore, except in areas where applications of brine, wetted salt, and wetted pre-mix are common, winter maintenance costs should not be a factor in the determination of pavement type.