The objective of this research is to evaluate and introduce a new methodology regarding rural highway safety. Current practices rely on crash prediction models that utilize specific explanatory variables, whereas the depository of knowledge for past research is the Highway Safety Manual (HSM). Most of the prediction models in the HSM identify the effect of individual geometric elements on crash occurrence and consider their combination in a multiplicative manner, where each effect is multiplied with others to determine their combined influence. The concepts of 3-dimesnional (3-D) representation of the roadway surface have also been explored in the past aiming to model the highway structure and optimize the roadway alignment. The use of differential geometry on utilizing the 3-D roadway surface in order to understand how new metrics can be used to identify and express roadway geometric elements has been recently utilized and indicated that this may be a new approach in representing the combined effects of all geometry features into single variables. This research will further explore this potential and examine the possibility to utilize 3-D differential geometry in representing the roadway surface and utilize its associated metrics to consider the combined effect of roadway features on crashes. It is anticipated that a series of single metrics could be used that would combine horizontal and vertical alignment features and eventually predict roadway crashes in a more robust manner. It should be also noted that that the main purpose of this research is not to simply suggest predictive crash models, but to prove in a statistically concrete manner that 3-D metrics of differential geometry, e.g. Gaussian Curvature and Mean Curvature can assist in analyzing highway design and safety. Therefore, the value of this research is oriented towards the proof of concept of the link between 3-D geometry in highway design and safety. This thesis presents the steps and rationale of the procedure that is followed in order to complete the proposed research. Finally, the results of the suggested methodology are compared with the ones that would be derived from the, state-of-the-art, Interactive Highway Safety Design Model (IHSDM), which is essentially the software that is currently used and based on the findings of the HSM.

Southeastern states have about 26 percent of the nations total fatalities, and are about 24 percent above the national mean over recent years. Descriptive statistics, graphs, and figures are used to illustrate and quantify the crash trends, which depict a comprehensive picture of status and trends of the fatal crashes in southeastern states. The severity of crashes is studied as a function of characteristics of the person involved in the crash, vehicle, traffic condition, physical road geometry, and environmental factors. Detailed geometric feature data were collected for this study, which makes it possible to investigate the relationship between geometric features and crash severity. This study identifies causal factors contributing to the high fatality rate in southeastern states, and sheds light on the differences and similarities among these states for reducing the severity of fatal crashes, by developing multinomial logit models to explain the severity and type of fatal crashes.

published_or_final_version / Public Administration / Master / Master of Public Administration

No description available.

No description available.

Thesis (M.S.)--University of Tennessee, Knoxville, 2008. / Title from title page screen (viewed on Sept. 23, 2009). Thesis advisor: Frank T. van Manen. Vita. Includes bibliographical references.

In this work we develop algorithms for the k-Supplier with Outliers problem. In a network, we are given a set of suppliers and a set of clients. The goal is to choose k suppliers so that the distance between every served client and its nearest supplier is minimized. Clients that are not served are called outliers and the number of allowed outliers is given on input. As k-Supplier with Outliers has numerous applications in logistics, we focus on parameters which are suitable for transportation networks. We study graphs with low highway dimension, which was proposed by Abraham et al. [SODA 2010], and low doubling dimension. It is known that unless P = NP, k-Supplier with Outliers does not admit a (3 − ε)-approximation algorithm for any constant ε > 0. The k-Supplier with Outliers problem is W[1]-hard on graphs of constant doubling dimension for parame- ters k and highway dimension. We overcome both of these barriers through the paradigm of parameterized approximation algorithms. In the case of highway dimension, we develop a (1 + ε)-approximation algorithm for any ε > 0 with running time f(k, p, h, ε) · nO(1) where p is the number of allowed outliers, h is the highway dimension of the input graph, and f is some computable function. In the case of doubling dimension, we develop a (1 + ε)-approximation...

No description available.

A highway construction cost index (HCCI) is an indicator of the purchasing power of a highway agency. Thus, it must reflect the actual construction market conditions. However, current methods used by most state departments of transportation are not robust enough to meet this primary goal due to (1) a significantly insufficient sample size of bid items used in HCCI calculation; and (2) inability to address the need to track highway construction market conditions in specific submarket segments such as, but not limited to, various project types, sizes, and locations. This study proposes an advanced methodology to overcome these apparent limitations using two new concepts: (1) dynamic item basket; and (2) multidimensional HCCIs. The dynamic item basket process identifies and utilizes an optimum amount of bid-item data to calculate HCCIs in order to minimize the potential error due to a small sample size, which leads to a better reflection of the current market conditions. Multidimensional HCCIs dissect the state highway construction market into distinctively smaller sectors of interest and thus, allow state Departments of Transportation to understand the market conditions with much higher granularity. A framework is developed to integrate these two concepts and a standalone prototype system, named the Dyna-Mu-HCCI System, is developed to automate the data-processing part of the framework. The historical bid data of the Montana Department of Transportation are used to evaluate the performance of the Dyna-Mu-HCCI System and measure the effects of the dynamic item basket (DIB) and multidimensional HCCIs. The results show an eightfold increase in terms of the number of bid items used in calculating HCCIs and at least a 20% increase in terms of the total cost of bid items used. In addition, the multidimensional HCCIs reveal different cost-change patterns from different highway sectors. For example, the bridge construction market historically shows a very different trend compared with the overall highway construction market. The new methodology is expected to aid state Departments of Transportation in making more-reliable decisions in preparing business plans and budgets with more accurate and detailed information about the construction market conditions. Further, the prototype Dyna-Mu-HCCI System is expected to significantly facilitate the HCCI calculation process and rapidly implement this new system.

<p>Истраживање&nbsp; у&nbsp; овом&nbsp; раду&nbsp; усмерено&nbsp; је&nbsp; на саобраћајни&nbsp; инфраструктурни&nbsp; коридор&nbsp; Београд&nbsp; -Нови Сад, Србија. Главни акценат је на изучавању односа&nbsp; пута&nbsp; и&nbsp; природе&nbsp; која&nbsp; је&nbsp; саставни&nbsp; део просторне целине којој аутопут припада. Рад има<br />за&nbsp; циљ&nbsp; да&nbsp; укаже&nbsp; на&nbsp; важност&nbsp; изучавања&nbsp; физичко-географских&nbsp; фактора&nbsp;&nbsp; приликом&nbsp; изградње саобраћајнице, ради остваривања што безбеднијег<br />саобраћаја.&nbsp; Посебан&nbsp; осврт&nbsp; је&nbsp; на&nbsp; климатске елементе,&nbsp; као&nbsp; не&nbsp; толико&nbsp; видљиве,&nbsp; али&nbsp; врло угрожавајуће&nbsp; факторе&nbsp; безбедности&nbsp; одвијања саобраћаја.&nbsp; Установљено&nbsp; је&nbsp; да&nbsp; се&nbsp; утицај климатских&nbsp; елемената&nbsp; може&nbsp; врло&nbsp; успешно контролисати&nbsp; вегетацијом,&nbsp; те&nbsp; је&nbsp; и&nbsp; ток истраживања&nbsp; био&nbsp; усмерен&nbsp; ка&nbsp; том&nbsp; правцу. Климатски&nbsp; подаци&nbsp; су&nbsp; преузети&nbsp; из&nbsp; CARPATCLIM базе,&nbsp; након&nbsp; чега&nbsp; се&nbsp; приступило&nbsp; њиховој<br />евалуацији.&nbsp; Добијени&nbsp; резултати&nbsp; су&nbsp; потврђени израдом&nbsp; ЧЕК-ЛИСТИ&nbsp; на&nbsp; терену&nbsp; и&nbsp; графичком обрадом&nbsp; података&nbsp; у&nbsp; GIS&nbsp; софтверском&nbsp; програму.Потом&nbsp; тога&nbsp; је&nbsp; уследило&nbsp; и&nbsp; анкетно&nbsp; истраживање безбедности одвијања саобраћаја на аутопутевима у Србији, посматрано из угла возача. Резултати су обрађени у SPSS софтверском програму.&nbsp; На крају, истраживање&nbsp; је&nbsp; истакло&nbsp; деонице&nbsp; саобраћајног<br />инфраструктурног&nbsp; коридора&nbsp; Београд&nbsp; &ndash;&nbsp; Нови&nbsp; Сад, најугроженије&nbsp; утицајима&nbsp; климатских&nbsp; елемената.Истакла&nbsp; се&nbsp; могућност&nbsp; ублажавања&nbsp; утицаја климатских&nbsp; елемената&nbsp; на&nbsp; безбедност&nbsp; одвијања саобраћаја&nbsp; предочавањем&nbsp; адекватног&nbsp; модела пејзажног&nbsp; уређења&nbsp; леве&nbsp; и&nbsp; десне&nbsp; стране&nbsp; коловоза пута.</p> / <p>Istraživanje&nbsp; u&nbsp; ovom&nbsp; radu&nbsp; usmereno&nbsp; je&nbsp; na saobraćajni&nbsp; infrastrukturni&nbsp; koridor&nbsp; Beograd&nbsp; -Novi Sad, Srbija. Glavni akcenat je na izučavanju odnosa&nbsp; puta&nbsp; i&nbsp; prirode&nbsp; koja&nbsp; je&nbsp; sastavni&nbsp; deo prostorne celine kojoj autoput pripada. Rad ima<br />za&nbsp; cilj&nbsp; da&nbsp; ukaže&nbsp; na&nbsp; važnost&nbsp; izučavanja&nbsp; fizičko-geografskih&nbsp; faktora&nbsp;&nbsp; prilikom&nbsp; izgradnje saobraćajnice, radi ostvarivanja što bezbednijeg<br />saobraćaja.&nbsp; Poseban&nbsp; osvrt&nbsp; je&nbsp; na&nbsp; klimatske elemente,&nbsp; kao&nbsp; ne&nbsp; toliko&nbsp; vidljive,&nbsp; ali&nbsp; vrlo ugrožavajuće&nbsp; faktore&nbsp; bezbednosti&nbsp; odvijanja saobraćaja.&nbsp; Ustanovljeno&nbsp; je&nbsp; da&nbsp; se&nbsp; uticaj klimatskih&nbsp; elemenata&nbsp; može&nbsp; vrlo&nbsp; uspešno kontrolisati&nbsp; vegetacijom,&nbsp; te&nbsp; je&nbsp; i&nbsp; tok istraživanja&nbsp; bio&nbsp; usmeren&nbsp; ka&nbsp; tom&nbsp; pravcu. Klimatski&nbsp; podaci&nbsp; su&nbsp; preuzeti&nbsp; iz&nbsp; CARPATCLIM baze,&nbsp; nakon&nbsp; čega&nbsp; se&nbsp; pristupilo&nbsp; njihovoj<br />evaluaciji.&nbsp; Dobijeni&nbsp; rezultati&nbsp; su&nbsp; potvrđeni izradom&nbsp; ČEK-LISTI&nbsp; na&nbsp; terenu&nbsp; i&nbsp; grafičkom obradom&nbsp; podataka&nbsp; u&nbsp; GIS&nbsp; softverskom&nbsp; programu.Potom&nbsp; toga&nbsp; je&nbsp; usledilo&nbsp; i&nbsp; anketno&nbsp; istraživanje bezbednosti odvijanja saobraćaja na autoputevima u Srbiji, posmatrano iz ugla vozača. Rezultati su obrađeni u SPSS softverskom programu.&nbsp; Na kraju, istraživanje&nbsp; je&nbsp; istaklo&nbsp; deonice&nbsp; saobraćajnog<br />infrastrukturnog&nbsp; koridora&nbsp; Beograd&nbsp; &ndash;&nbsp; Novi&nbsp; Sad, najugroženije&nbsp; uticajima&nbsp; klimatskih&nbsp; elemenata.Istakla&nbsp; se&nbsp; mogućnost&nbsp; ublažavanja&nbsp; uticaja klimatskih&nbsp; elemenata&nbsp; na&nbsp; bezbednost&nbsp; odvijanja saobraćaja&nbsp; predočavanjem&nbsp; adekvatnog&nbsp; modela pejzažnog&nbsp; uređenja&nbsp; leve&nbsp; i&nbsp; desne&nbsp; strane&nbsp; kolovoza puta.</p> / <p>The&nbsp; research&nbsp; in&nbsp; this&nbsp; paper&nbsp; focuses&nbsp; on&nbsp; the&nbsp; highway corridor Belgrade&nbsp; -&nbsp; Novi Sad, Serbia. The main issue is relationship between the highway and surrounding nature, as an integral part of the spatial entity which the highway belongs to. In order to achieve high level of&nbsp; the&nbsp; traffic&nbsp; safety,&nbsp; the&nbsp; paper&nbsp; emphasizes&nbsp; a&nbsp; high importance&nbsp; of&nbsp; studying&nbsp; the&nbsp; physical-geographical factors&nbsp; in&nbsp; the&nbsp; process&nbsp; of&nbsp; highway&nbsp; construction. Particular attention was directed to, not so visible, but very&nbsp; endangering&nbsp; factors&nbsp; of&nbsp; road&nbsp; safety&nbsp; -&nbsp; climate elements.&nbsp; It&nbsp; was&nbsp; found&nbsp; that&nbsp; the&nbsp; influence&nbsp; of&nbsp; climate elements&nbsp; is&nbsp; strong&nbsp; and&nbsp; it&nbsp; could&nbsp; be&nbsp; successfully controlled&nbsp; by&nbsp; vegetation.&nbsp; Data&nbsp; were&nbsp; taken&nbsp; from CARPATCLIM&nbsp; database&nbsp; and&nbsp; their&nbsp; evaluation &nbsp; was confirmed by obtained field data in CHEK-LISTS and by&nbsp; data&nbsp; evaluation&nbsp; in&nbsp; GIS.&nbsp; This&nbsp; was&nbsp; followed&nbsp; by&nbsp; a survey on the traffic safety of the highways in Serbia,from&nbsp; the&nbsp; driver&#39;s&nbsp; aspect&nbsp; of&nbsp; view.&nbsp; Results&nbsp; were processed&nbsp; in&nbsp; the&nbsp; SPSS.&nbsp; Finally,&nbsp; the&nbsp; research emphasized&nbsp; the&nbsp; most&nbsp; endangered&nbsp; sections&nbsp; of&nbsp; the traffic&nbsp; infrastructure&nbsp; corridor&nbsp; Belgrade&nbsp; -&nbsp; Novi&nbsp; Sad,affected by the climate elements. Landscape design of left and right side of the highway has been highlighted as a possibility of mitigating the influence of climate elements.</p>