The study of the traffic noise as an environmental impact, the search for solutions to this problem, and the development of noise measurement methodologies that help in the search of these solutions, is now a fundamental responsibility for the transportation industry.   So, in line with this responsibility, consistent work was made with focus on tire/pavement noise measured over different pavement surfaces, and under different environmental conditions, and different speeds. In a parallel way, work was conducted for the development, improvement, and practical use of the On- Board Sound Intensity (OBSI) methodology for tire/pavement noise measurements.   The first part of this thesis shows the results of field experimentation about the influence of external factors like air temperature and vehicle speed over the tire/pavement noise measured with the OBSI methodology. Temperatures from 40 to 90"F were targeted, and speeds from 35 mph to 60 mph (range in which tire/pavement noise becomes predominant for the overall vehicle noise) were tested. For this work a series of seasonal field tests were conducted on a primary road in Virginia over various months.  The results were analyzed to quantify the variation of tire/pavement noise with respect to the air temperature and test speed, and therefore to find correction factors for this variables in order to normalize the data taken under different conditions. In the second part of this thesis, the study of tire/pavement noise over different surfaces and measured over a timeframe of three seasons is presented. This part presents results about noise reduction potentials of two proposed "quiet" concrete technologies and 3 proposed "quiet" asphalt surfaces when compared with one another, and with control sections. Also the second part of the thesis includes results about the susceptibility of the proposed surfaces to external factors such as: aging (three seasons involved), air temperature differentials and winter maintenance. In general, the findings show trends that tire/pavement noise slightly decreases as air temperature increases. A gradient of approximately -0.05 dBA/"F was found. It was found as well that tire/pavement noise increases an average of 2.5 dBA for every 10 mph of increased speed.   The statistical analysis results for the second part of the thesis shows that all proposed concrete surfaces and asphalt surfaces present benefits in terms of noise reduction, For the asphalt surfaces, it was found that more voids in the surface helps to absorb the noise. In addition, the rubber modified mixes show an improved noise reduction potential. Air temperature normalization was performed an a statistical analysis was conducted; it was found that air temperature has a significant influence in the noise measurements especially for the first months of use. Finally it was found that there is a slightly increase in noise over time after the first months of use. / Master of Science

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Dedicated short-range communication (DSRC) systems, a form of vehicle-to-everything (V2X) systems, were placed on Utah Department of Transportation (UDOT) snowplows to request signal preemption. The study took place along five state routes in the Salt Lake City metropolitan area. Snowplows and intersections were equipped with the technology to communicate and process requests for signal preemption. Signal performance and vehicle performance analysis were performed to understand the impacts that snowplows requesting signal preemption had. Signal performance analysis was done to determine how snowplows with V2X systems using DSRC affected signals. Vehicle performance analysis was done to see if plowing and traffic efficiency and performance were improved, as well as evaluating safety implications of signal preemption. To perform the signal performance analysis, V2X data were collected to understand how often signal preemption was requested by snowplows, how often it was granted by signal controllers, and how long preemption requests affected signal controller timing. Snowplows requested preemption over 50 percent of the time they approached a signalized intersection. Of messages that requested signal preemption, over 80 percent were granted. On average, signal controllers are affected by preemption processing for less than 5 minutes. This shows that the system works as designed, is used often, and does not have adverse effects on signal controller. Data for vehicle performance analysis included analysis of snowplow speed data, general travel speed data, and crash data. These were collected to analyze the effects of snowplows requesting signal preemption on vehicle performance. The analysis showed that snowplow speeds are not changed due to the signal preemption system, but the number of times snowplows stopped was reduced. General travel speeds on equipped routes were more consistently closer to the speed limits than not equipped routes. Crash data showed a greater negative decrease on equipped routes than on not equipped routes. These findings showed minimal changes or impacts to vehicle performance, but anecdotal evidence from snowplow drivers indicates benefits from the system overall. There were various limitations in the analysis. Data granularity differed among datasets, making comparison between the different datasets difficult without reducing data integrity. Some datasets did not have much data, making statistical significance unclear. With these data limitations, conclusions were drawn, but do not fully describe all the potential benefits and impacts of snowplows with V2X systems that use DSRC to request signal preemption. Additional research is needed to better understand the impacts that snowplows requesting signal preemption has on different maintenance metrics, such as fuel usage and time spent plowing. It is also recommended that data used is explored for ways to improve the granularity.

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Sverige behöver öka andelen hållbara resor för att minska den negativa påverkan på miljön. Två positiva effekterna med cykling är den förbättrade folkhälsan och att det är mer energieffektivt än att resa med bil. Idag är omkring 40% av alla bilresor kortare än 5km. Antalet cykelresor är färre under vintern och därför är potentialen som störst att ersätta kortare bilresor vintertid. Cyklister har en högre risk än bilister att skadas eller dödas och därför är det viktigt, i arbetet mot ökad cykling att även förbättrad säkerhet för cyklister. Studier av Statens väg- och transportforskningsinstitut (VTI) visar att fler väljer att cykla vintertid om vinterunderhållet är bra. I den traditionella vinterväg-hållningen används plogning och sand. Sopsaltmetoden har ökat i popularitet. Metoden använder en borste för att sopa bort snön och saltlösning, torrt eller befuktat salt för halkbekämpning. Det leder till barmarksförhållanden vintertid (utan sand som ökar risken för halkolyckor) ökad tillgänglighet och bättre komfort för cyklister. Metoden är dock mer resurskrävande och sprider salt till miljön. Syftet med denna studie är att undersöka hur vinterväghållningen kan utformas i Avesta kommun för att öka det hållbara resandet och få fler att cykla på vintern. Förutsättningarna för att implementera metoden i mindre kommuner diskuteras. Rekommendationerna specifika för Avesta kommun kan användas av andra kommuner som funderar på att implementera sopsaltmetoden. Genom en litteraturstudie sammanställs tillgänglig forskning och erfarenheter från kommuner som använt sopsaltmetoden. För att samla in mer erfarenhet inbjöds kommunerna att delta i en enkätstudie. Även en fallstudie genomförde där Avestas förutsättningar att implementera metoden analyserades. Tre intervjuer hölls, en med Avesta kommun, en med Katrineholms kommun som tidigare använt metoden och en med två av de ledande forskarna inom sopsaltmetoden Anna Niska och Göran Blomqvist från VTI.   19 av de 27 inbjudna kommunerna deltog i enkäten som bland annat visade att 74% av kommunerna valt att förlänga längden på de sopsaltade stråken. Främst till följd av den stora efterfrågan från kommuninvånare och den politiska viljan att prioritera cykling i kommunen. Den empiriska evidensen som samlats in via de använda metoderna användes för att besvara studiens syfte. Trots att flödesmätningar inte kunnat bevisa det i siffror till följd av det begränsade underlaget, anses implementering av sopsaltmetoden öka andelen cykelresor vintertid. Metodens största fördel är den ökade komforten och tillgängligheten som skapas för cyklister. Den högre kostnaden ska sättas i relation till samhällets kostnader för halkolyckor och vinsten i en förbättrad folkhälsa. I kombination med det förändrade klimatet som kräver mer halkbekämpning rekommenderas Avesta kommun att implementera sopsaltmetoden. Huvudcykelstråken som definieras i cykelplanen ska prioriteras i vinterväghållningen. Med de stora investeringar som planeras för Kyrkbron i åtanke, är det lämpligt att implementera sopsaltmetoden på angränsande stråk. Tanken att inkludera värme och kombinera med sopning är intressant och Avesta rekommenderas att ta med det i projekteringen av bron. Med rådande ekonomiska läget kan det förståeligt vara svårt att prioritera implementeringen av en ny, dyrare metod. Då bör metoden ses som en möjlig metod för att prioritera det hållbara resandet i framtiden. En mindre kommun har sina specifika styrkor och svagheter, bland annat är besluts- och kontaktvägar kortare. Den största svagheten är resursutmaningarna som finns i en mindre kommun. / Sweden needs to increase the proportion of sustainable travels to decrease the negative impact on the environment. Among the great effects of cycling are the positive effects on the public health and that it is more energy efficient compared to travelling by car. Today about 40% of all car journeys are shorter than 5km. Bicycle travels decrease during winter and therefor the potential in increasing sustainable travel by replacing shorter car travels is highest during winter. Since cyclists have a higher risk to get injured or killed compared to motorists it is important when working for more bicycle travels to also improve the safety for cyclists. Studies by the Swedish National Road and Transport Research Institute (VTI) shows that more people choose to cycle during winter if the winter maintenance is good. The traditional method is to clear the snow by ploughing and skid control by using grit. The method sweepsalting has increased in popularity. A machine uses a power broom to clear the snow and spreads saline solution or pre-wetted salt for skid control. It leads to bare ground conditions during winter, with no grit that increases risk for accidents, an increased accessibility and it is more comfortable for cyclists. The method is however more resource demanding and salt is spread to the environment. The aim of this study is to investigate how winter maintenance can be designed in Avesta municipality to increase sustainable travel and get more people to cycle in the winter. A discussion of the prerequisites for implementation of the sweepsalting method in smaller municipalities is conducted. The resulting recommendations specific to Avesta can be used by other municipalities thinking of implementing the sweepsalting method. Through a literature review, available research on the sweepsalting method and experiences from other municipalities was compiled. To gather more experience municipalities were invited to participate in a survey study. A case study to analyse the possibility to include sweepsalting in Avesta was also conducted. Three interviews were held, one with Avesta municipality, one Katrineholms municipality which previously used the method and one with two of the leading researchers in sweepsalting Anna Niska and Göran Blomqvist at VTI.  19 of the 27 municipalities invited participated in the survey. For example, the survey showed that 74% of the municipalities have chosen to increase the length of the sweepsalted cycleways mainly due to the high demand from the public and from politicians wanting to prioritize cycling. The empirical evidence gathered by the methods was used to answer the aim of the study. Implementing the sweepsalting method increases bicycle travels during winter, this even though flow measurements have not been able to clearly prove this in numbers due to the insufficient basis. The biggest advantage is the increased comfort and accessibility created for cyclists. The higher cost must be placed in relation to the costs for accidents and to increased public health. This, combined with the changing climate, demanding more slip control, the implementation of sweepsalting is recommended in Avesta. The main cycle routes defined in the cycle plan should be prioritized in the winter maintenance. With the major investments planned for Kyrkbron in mind, it is suitable to combine it with implementing of the sweepsalting method on connecting cycleways. The idea of heating the bridge surface when rebuilding the bridge and combining it with sweeping of the surface is interesting and Avesta is recommended to include it in the planning. With the current economic situation, it can understandably be difficult to prioritize implementing a new, more expensive method. If so, the method should be seen as a possible future method prioritizing and facilitating sustainable travels. A smaller municipality has its strengths and its weaknesses, the decision paths and contact paths are often shorter than in bigger municipalities. The biggest drawback is the resource challenges in smaller municipalities.

Because winter maintenance is so costly, Utah Department of Transportation (UDOT) personnel asked researchers at Brigham Young University to determine whether asphalt or concrete pavements require more winter maintenance. Differing thermal properties suggest that, for the same environmental conditions, asphalt and concrete pavements will have different temperature profiles. Climatological data from 22 environmental sensor stations (ESSs) near asphalt roads and nine ESSs near concrete roads were used to 1) determine which pavement type has higher surface temperatures in winter and 2) compare the subsurface temperatures under asphalt and concrete pavements to determine the pavement type below which more freeze-thaw cycles of the underlying soil occur. Twelve continuous months of climatological data, primarily from the 2009 calendar year, were acquired from the road weather information system operated by UDOT, and erroneous data were removed from the data set. To predict pavement surface temperature, a multiple linear regression was performed with input parameters of pavement type, time period, and air temperature. Similarly, a multiple linear regression was performed to predict the number of subsurface freeze-thaw cycles, based on month, latitude, elevation, and pavement type. A finite-difference model was created to model surface temperatures of asphalt and concrete pavements based on air temperature and incoming radiation. The statistical analysis predicting pavement surface temperatures showed that, for near-freezing conditions, asphalt is better in the afternoon, and concrete is better for other times of the day, but that neither pavement type is better, on average. Asphalt and concrete are equally likely to collect snow or ice on their surfaces, and both pavements are expected to require equal amounts of winter maintenance, on average. Finite-difference analysis results confirmed that, for times of low incident radiation (night), concrete reaches higher temperatures than asphalt, and for times of high incident radiation (day), asphalt reaches higher temperatures than concrete. The regression equation predicting the number of subsurface freeze-thaw cycles provided estimates that did not correlate well with measured values. Consequently, an entirely different analysis must be conducted with different input variables. Data that were not available for this research but are likely necessary in estimating the number of freeze-thaw cycles under the pavement include pavement layer thicknesses, layer types, and layer moisture contents.