Construction zones can greatly affect the traffic flow on roadways, especially when lane closures are required. Traditionally, the Utah Department of Transportation (UDOT) has used traffic management specifications that only allow lane closures and road work to be done during predetermined hours or specifications that require a certain number of lanes to be open at all times. Recently, mobility-based work-zone traffic flow maintenance has been considered. This method requires continuous monitoring of mobility-based performance data and a mechanism to send alerts to the contractors when the mobility data does not meet the standards set by the specifications. UDOT recently tested mobility-based performance specifications at an urban arterial work zone and studied issues related to implementation of mobility-based performance specifications. Parallel to this experiment, UDOT funded a study to develop guidelines for implementing mobility-based performance specifications to manage traffic flow in work zones. Dynamically collecting mobility-based data such as travel time and speed is now feasible using technologies such as Bluetooth and microwave sensors. The core benefit of using mobility-based performance specifications is that they can give the contractor more flexibility in construction work scheduling while maintaining an acceptable level of traffic flow. If the level of traffic flow is not maintained, then the contractor is assessed a financial penalty. The penalty is determined by the amount of time where the flow is not maintained at a predetermined condition. To discuss issues and develop guidelines, a task force consisting of UDOT representatives, several representatives from the construction industry, and researchers from Brigham Young University was formed. Through three task force meetings, a set of 12 guidelines were developed, including guidelines about when mobility-based performance specifications should be used and which mobility data should be used. Some of the issues were difficult for the task force members to agree on, and a decision-making theory called the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was used to find best approaches to deal with some of the difficult issues associated with the implementation of mobility-based performance specifications in highway construction contracts. These guidelines should be reviewed as appropriate in the future as UDOT accumulates experience in using these types of specifications.

The monetary quantification of inconveniences caused to the road users by ongoing construction activities is known as the Road Users Costs (RUCs). While the importance of RUCs is widely known, some highway agencies lack an appropriate methodology to compute RUCs. Thus, there is a need to develop a framework to compute RUCs that can be adopted quickly by highway agencies. This study reviewed existing literature and conducted a nationwide survey to identify and summarize the current practices of computing RUCs. It developed an enhanced framework and tool to compute RUCs that balances the effort required to calculate RUCs and the accuracy of the results. This enhanced framework accounts for the spatiotemporal variation of RUCs. The results of the study are expected to enable highway agencies to quickly and accurately compute RUCs to make better project management decisions, such as selecting the best contractor that minimizes the agency costs and RUCs.

No description available.

Purpose: There are many different risks while working on or close to roads. This is because conditions are very varying on road works and different tasks are being performed at the same time (AV, 2015). According to a survey carried out by SEKO (2011) seven out of ten road workers are worrying about working on or close to roads because of the lack of safety. But the fear is not groundless, according to a survey carried out by Liljegren and Szafran-Kzdrój (2014) 2935 accidents related to road works happened between year 2003-2012 where road workers were involved in 139 of the total cases. Efforts to create a better work environment are taking place daily but there are still road workers that get injured or even killed during work. The aim with this report is therefore to examine how roadworkers safety can be improved during roadworks. Method: This survey is a case study, which aims to illustrate the reality. In order to answer the questioning formulation, three different methods have been used. A literature study was first completed to understand how far previous research has come and after that a document analysis of valid laws and regulations was made. The third method used was qualitative interviews, which is the most important foundation for the result. Findings: Risks that occur in road work zones often arises because of the passing traffic. High speed along with reckless drivers or drivers that act aggressive are great risk factors. These risk factors also contribute to mental illness such as stress and anxiety. Physical problems are also a cause of bad work environment with dusty or noisy surroundings. The shared solution to solve these problems are diversion or to reduce speed even more past road work zones. This is though easier said than done because the road maintenance often wats to keep a high traffic volume during the time a road work is performed. Implications: Risks in road work zones are lower when a traffic diversion is applied or when traffic can pass in a satisfactory way. Unfortunately, these actions are not being applied in such extent as wanted by the road workers. To minimise risks in road work zones the contractors' have to start compile and together ask for higher standards. When traffic diversion can’t be applied must recommended speed be reduced even more. Limitations: All interviews were conducted with people working in the same company but in different business areas, within the county of Jönköping. This was because different opinions about the problem were asked for. It is though difficult to decide whether or not the result is generalizable, because only people within the same county and company were interviewed. / Syfte: När vägarbeten utförs på och intill vägar är riskerna många eftersom platsen varierar samtidigt som flera olika arbetsuppgifter utförs samtidigt (AV, 2015). Enligt en undersökning gjord av SEKO (2011) oroar sig sju av tio vägarbetare för att arbeta på väg på grund av bristande säkerhet. Oron är dessvärre inte obefogad, en studie utförd av Liljegren och Szafran-Kzdrój (2014) visar att det under år 2003-2012 inträffade 2935 olyckor relaterade till vägarbeten och i 139 av fallen var vägarbetare inblandade. Arbetet med att skapa en bättre arbetsmiljö pågår dagligen men det sker ändå att vägarbetare skadas eller omkommer på sin arbetsplats. Målet med arbetet är därför att undersöka hur säkerheten för vägarbetare kan förbättras vid arbete på väg. Metod: Undersökningen är av typen fallstudie, vilket syftar till att belysa verkligheten. För att besvara frågeställningarna och uppnå målet har tre olika metoder använts. Först genomfördes en litteraturstudie för att undersöka var kunskapsfronten inom ämnet ligger idag, därefter gjordes en dokumentanalys av gällande lagar, förordningar och föreskrifter. Den tredje metoden som användes var kvalitativa intervjuer, vilka utgör det största underlaget till resultatet. Resultat: De risker som finns på vägarbetsplatser uppkommer till stor del på grund av den passerande fordonstrafiken. Höga hastigheter är tillsammans med trafikanter som kör hänsynslöst eller uppvisar ett aggressivt beteende stora riskfaktorer. Dessa riskfaktorer bidrar även till att psykiska problem som exempelvis stress och oro uppstår. Även fysiska problem på grund av en dålig arbetsmiljö med damm och buller förekommer. Den gemensamma lösningen är kort “led om trafiken” eller “sänk hastigheten ytterligare förbi vägarbetsplatser”. Det är dock lättare sagt än gjort eftersom väghållaren ofta vill behålla en hög trafikvolym på vägarna samtidigt som vägarbeten utförs. Konsekvenser: När trafiken leds om eller kan passera på ett betryggande sätt minskar riskerna på vägarbetsplatsen, dock görs inte detta i tillräcklig stor utsträckning. För att minska riskerna måste entreprenadföretag samarbeta mer och börja ställa högre krav på väghållaren. Vid de tillfällen då trafiken inte kan ledas om utan måste passera vägarbetsplatsen ska även den rekommenderade hastigheten sänkas i större utsträckning. Begränsningar: Alla intervjuer är genomförda med personer som arbetar på samma företag men inom olika affärsområden inom Jönköpings län. Detta eftersom olika ställningstagande om problemet eftersöktes. Då enbart personer som arbetar inom samma län och företag intervjuats är det svårt att avgöra om resultatet är generaliserbart för andra län och företag av annan storlek.

Doctor of Philosophy / Civil Engineering / Sunanda Dissanayake / Safe and efficient flow of traffic through work zones must be established by improving work zone conditions. Therefore, identifying the factors associated with the severity and the frequency of work zone crashes is important. According to current statistics from the Federal Highway Administration, 2,372 fatalities were associated with motor vehicle traffic crashes in work zones in the United States during the four years from 2010 to 2013. From 2002 to 2014, an average of 1,612 work zone crashes occurred in Kansas each year, making it a serious concern in Kansas. Objectives of this study were to analyze work zone crash characteristics, identify the factors associated with crash severity and frequency, and to identify recommendations to improve work zone safety. Work zone crashes in Kansas from 2010 to 2013 were used to develop crash severity models. Ordered probit regression was used to model the crash severities for daytime, nighttime, multi-vehicle and single-vehicle work zone crashes and for work zones crashes in general. Based on severity models, drivers from 26 to 65 years of age were associated with high crash severities during daytime work zone crashes and driver age was not found significant in nighttime work zone crashes. Use of safety equipment was related to reduced crash severities regardless of the time of the crash. Negative binomial regression was used to model the work zone crash frequency using work zones functioned in Kansas in 2013 and 2014. According to results, increased average daily traffic (AADT) was related to higher number of work zone crashes and work zones in operation at nighttime were related to reduced number of work zone crashes. Findings of this study were used to provide general countermeasure ideas for improving safety of work zones.

No description available.

When roadworks are performed, one of the impacts is delays in the traffic. Partly because of reduced speed limits past the work zones but mainly because of the facility's limited quality of service. This could result in significant delays for the road users with lost work and spare time as a consequence. The lost time in congestions could have been used more efficiently. It is therefore of interest to estimate these delays for different types of roadworks to calculate its macro economical impact. The estimations may be a factor in different types of planning, for example in roadwork planning, in work zone scheduling or in life cycle assessments. The estimations can be conducted using different methods, such as analytical, queuing theory or macrosimulation. However, to include the details of specific work zones an analysis method of higher detail is required. First to include varying geometric details, secondly due to the higher level of detail in the representation of the traffic. Therefore may microsimulation be a suitable analysis method. The purpose of this master thesis was to investigate microsimulations suitability for work zone analysis, by using the software AIMSUN. AIMSUN were different work zone types modeled, first of highways. Later was a 2-lane road modeled for which the traffic control was a fixed signal, then controlled by a simpler extension developed in C++ that simulated a flagger control. Using a developed helper program, the work zone models could be simulated for a large set of daily flow levels and heavy vehicle ratios. Together with corresponding results for normal conditions, it was possible to calculate the delays. The results were relationships between the total delays, for various heavy vehicle ratios. A concern with the results was deviations of the delays for different daily flows and heavy vehicle ratios. Even if the deviations will not have any greater impact on the total cost, they may be unwanted in decision models. Processing of the result may therefore be necessary. This master thesis has showed that microsimulation may be a suitable method to analyze work zone impacts. Using the high level of detail, work zones special character can be captured. Possible future work is to improve the reliability of results by performing validations of results with real work zone data to compare speeds, headways and queue lengths. Additional work may include to consider the diversion delays. / När vägarbeten utförs uppkommer fördröjningar i trafiken. Delvis på grund av reducerade hastigheter förbi arbetsområdet men i huvudsak på grund av minskad framkomlighet. Det kan resultera i betydande fördröjningar för trafikanterna med förlorad arbets- och fritid som följd.  Den förlorade tiden i köer kunde då ha använts effektivare. Det är då av intresse att kunna uppskatta fördröjningarna vid olika typer av vägarbeten för att beräkna dess samhällsekonomiska påverkan. Uppskattningarna kan då vara en faktor vid beslut inom olika typer av planering, till exempel vid vägarbetsplanering, schemaläggning eller livscykelanalyser. För att göra dessa uppskattningar kan olika metoder användas, till exempel analytiskt, med köteori eller makrosimulering. Men för att kunna inkludera detaljerna vid olika vägarbeten krävs en analysmetod med högre detaljnivå. Dels för att få med geometriska detaljer, dels detaljnivån i representation av trafiken. Då kan mikrosimulering vara en lämplig metod. Syftet med det här examensarbetat var att undersöka mikrosimulerings användbarhet vid vägarbetesanalyser, det genom att använda programvaran AIMSUN. I AIMSUN modellerades olika typer av vägarbeten, först för motorvägar. Sedan modellerades en 2-fältsväg där trafikkontrollen dels sköttes av en skyttelsignal, sedan utvecklades ett enklare tillägg i C++ som simulerade en flaggvakt som istället skötte trafikkontrollen. Med hjälp av ett utvecklat program kunde modellerna simuleras för en stor mängd olika dygnsflöden och andel tung trafik. Tillsammans med motsvarande grundscenario kunde fördröjningarna beräknas. Resultaten blev samband mellan totala fördröjningen under dagen beroende på dygnsflödet, det för olika andelar tung trafik. Ett bekymmer med resultaten var variationer i fördröjningarna mellan olika dygnsflödesnivåer och andelar tung trafik. Även om variationerna inte ger så stort utslag på totala kostnaden, så kan variationerna vara icke önskvärda i till exempel beslutsmodeller. En viss bearbetning av resultaten kan då vara nödvändig. Det här examensarbetet har visat att mikrosimulering kan vara en lämplig metod för att analysera vägarbetens påverkan. Med dess höga detaljnivå har vägarbetenas olika karaktär kunnat återskapas. Möjligt framtida arbete är att öka pålitligheten i resultaten genom validation med trafikdata från verkliga vägarbeten med jämförelser mellan hastigheter, avstånd och kölängder. Ytterligare arbete kan vara att uppskatta fördröjningar av att fordon väljer omvägar för att undvika vägarbetenas köer.

The diploma thesis deals with the behaviour of traffic stream at work zones. It focuses primarily on alternating arranging just before funnelling of the traffic and creation of congestions. The study of parameters defined in the Aimsun program, that examines their effect on alternating arranging in micro-simulation, is a part of the thesis. The right setting of values is verified on traffic model formulated on the basis of video recording. The work aims to minimize effects of necessary repairs and reconstructions of roads by the telematic applications which dynamically affect the traffic stream by changing the maximum speed.

<p>  </p> <p>Highway workers are required to work close to moving traffic during road construction and maintenance activities, which exposes them to the risk of being struck by a distracted driver or intruding vehicle. In addition, work zones disturb the usual traffic flow and patterns due to changes in the existing geometric layout of a roadway, and this is also problematic for the drivers as they must navigate a layout of signs, barrels, and lane changes while keeping the vehicle in control. Moreover, late-night tasks, reckless driving, inconsistent work zones, drunk driving, and increased vehicle miles traveled are some of the additional causes of work zone incidents in the United States. Nationwide, around 40,000 accidents occur each year in highway work zones due to vehicle intrusion into the work zone and have steadily increased during the past ten years. Most often, the driver and passenger of the vehicle are the victims of such accidents. The resulting fatalities, injuries, and property damage due to such incidents lead to significant expenses, prolonged travel delays, and potential damage to expensive products in transit.</p> <p>While traditional safety precautions (e.g., truck-mounted attenuators, rumble strips, speed monitoring displays) can help enhance work zone safety, the number of work zone intrusions calls for designing and implementing emerging intrusion alert technologies to warn drivers and workers when errant vehicles intrude into the work zone. Several state Departments of Transportation (DOTs) have begun examining the use of intrusion alert technologies to mitigate work zone intrusions. While previous studies examined the general effectiveness (e.g., sound levels, work zone coverage, deployment characteristics, etc.) of these technologies in both controlled and active construction and maintenance work zones, there are still significant research gaps in investigating how well these intrusion technologies alert the driver and workers, and no documented best practices are available for transportation agencies and DOTs interested in implementing them. In addition, these technologies have been through many improvements and modifications, and further research is imperative to ascertain their chances of acceptance by workers and contractors.</p> <p>To address these gaps, this thesis focuses on (a) empirically examining the effectiveness, implications, and practices of four commercially available intrusion technologies in enhancing work zone safety through various field tests and surveys, and (b) empirically investigating the effectiveness of these technologies considering drivers’ cognitive processing (perception -reaction time) and responses in case of work zone intrusion. The findings of this research study provide detailed information on the identification and testing procedures of technologies and offer guidelines and recommendations for adopting these technologies for practitioners and professionals in the highway construction sector. The proposed decision-making matrix and multi-criteria decision-making framework are based on the empirical data obtained from the various field experiments, literature review, and evaluation survey. This study also provides valuable insights into the overall effectiveness (i.e., by considering functional characteristics, associated drivers’ responses and reactions, and current implementation) of commercially available intrusion technologies to incorporate required modifications in designing and implementing these technologies to enhance work zone safety. The long-term outcome of this study is to significantly reduce the injuries and fatalities in highway maintenance work zones in Indiana and across the country.</p>