Use of Stream and Dismembered Stream Valleys Now Crossing Wyoming’s Northern Laramie Mountains to Test a Recently Proposed Regional Geomorphology Paradigm, USA

Detailed topographic maps show multiple stream valleys and what are probably dismembered stream valleys that extend completely across Wyoming’s northern Laramie Mountains. Several of the most obvious valleys are described with valley origins first explained (or attempted to be explained) from the commonly accepted regional geomorphology paradigm (accepted paradigm) perspective and second from a recently proposed regional geomorphology paradigm (new paradigm) perspective in an effort to determine which of the two paradigms provides the simplest explanations. Accepted paradigm explanations require at least some of the valley erosion to have occurred prior to deposition of Oligocene and Miocene sediments that once covered the northern Laramie Mountains (with some of the exhumed valleys now containing sediment cover remnants). In contrast the fundamentally different new paradigm requires immense south-oriented continental ice sheet melt water floods to have crossed the region as ice sheet related crustal warping raised the region and the Laramie Mountains (and implies sediments now partially filling some of the valleys are probably flood deposited materials). The new paradigm provides simpler explanations for the origins of the valleys now extending completely across the northern Laramie Mountains and also for their related barbed tributaries, truncated side valleys, and drainage route U-turns than the accepted paradigm, although the new paradigm also leads to a fundamentally different middle and late Cenozoic regional geologic history than is currently recognized. One paradigm cannot be used to judge a different paradigm, but the paradigms can be compared based on their ability to explain evidence and Occam’s Razor can determine which of the two paradigms provides the simplest explanations. New paradigm explanations for northern Laramie Mountains valley origins investigated here require fewer assumptions than the accepted paradigm explanations suggesting the new paradigm merits serious future consideration.

Estimating traffic volume on Wyoming low volume roads using linear and logistic regression methods

Traffic volume is an important parameter in most transportation planning applications. Low volume roads make up about 69% of road miles in the United States. Estimating traffic on the low volume roads is a cost-effective alternative to taking traffic counts. This is because traditional traffic counts are expensive and impractical for low priority roads. The purpose of this paper is to present the development of two alternative means of cost- effectively estimating traffic volumes for low volume roads in Wyoming and to make recommendations for their implementation. The study methodology involves reviewing existing studies, identifying data sources, and carrying out the model development. The utility of the models developed were then verified by comparing actual traffic volumes to those predicted by the model. The study resulted in two regression models that are inexpensive and easy to implement. The first regression model was a linear regression model that utilized pavement type, access to highways, predominant land use types, and population to estimate traffic volume. In verifying the model, an R^2 value of 0.64 and a root mean square error of 73.4% were obtained. The second model was a logistic regression model that identified the level of traffic on roads using five thresholds or levels. The logistic regression model was verified by estimating traffic volume thresholds and determining the percentage of roads that were accurately classified as belonging to the given thresholds. For the five thresholds, the percentage of roads classified correctly ranged from 79% to 88%. In conclusion, the verification of the models indicated both model types to be useful for accurate and cost-effective estimation of traffic volumes for low volume Wyoming roads. The models developed were recommended for use in traffic volume estimations for low volume roads in pavement management and environmental impact assessment studies.

Performance evaluation framework of Wyoming connected vehicle pilot deployment program: summary of Phase 2 pre-deployment efforts and lessons learned

Purpose–This paper aims to present a summary of the performance measurement and evaluation plan of the Wyoming connected vehicle(CV)Pilot Deployment Program(WYDOT Pilot).Design/methodology/approach–This paper identified 21 specific performance measures as well as approaches to measure the benefits of the WYDOT Pilot.An overview of the expected challenges that might introduce confounding factors to the evaluation effort was outlined in the performance management plan to guide the collection of system performance data.Findings–This paper presented the data collection approaches and analytical methods that have been established for the real-life deployment of the WYDOT CV applications.Five methodologies for assessing 21 specific performance measures contained within eight performance categories for the operational and safety-related aspects.Analyses were conducted on data collected during the baseline period,and pre-deployment conditions were established for 1 performance measures.Additionally,microsimulation modeling was recommended to aid in evaluating the mobility and safety benefits of the WYDOT CV system,particularly when evaluating system performance under various CV penetration rates and/or CV strategies.Practical implications–The proposed performance evaluation framework can guide other researchers and practitioners identifying the best performance measures and evaluation methodologies when conducting similar research activities.Originality/value–To the best of the authors’knowledge,this is thefirst research that develops performance measures and evaluation plan for low-volume rural freeway CV system under adverse weather conditions.This paper raised some early insights into how CV technology might achieve the goal of improving safety and mobility and has the potential to guide similar research activities conducted by other agencies.

Modeling traffic barriers crash severity by considering the effect of traffic barrier dimensions

Traffic barriers are in widespread all around the USA as safety countermeasures for reducing the severity of run-off-road crashes. The effect of traffic barriers’ dimension had been ignored in past real-world crash studies due to the considerable cost and time needed for collecting field data. This paper presented two new analytical models to investigate the effect of different variables on the severity of crashes involving traffic barriers, and end treatments. For this reason, a field survey was conducted on over 1.3 million linear feet of traffic barriers (approximately 4,176 miles road) in Wyoming to measure traffic barriers’ geometric features like height, length, offset, and slope rate. The collected data included 55% of all non-interstate roads of Wyoming. Based on results, the crashes involving box beam barriers were less severe than the crashes involved with W-beam or concrete barriers. The traffic barriers with a height between 28 and 31 in. were found safer than the traffic barriers shorter than 28 in., while there was no significant difference between the traffic barriers taller than 31 in. to those shorter than 28 in. in terms of crash severity. The end treatments located nearer to the traffic lane had lower crash severity.

A global comparison of V_(p),V_(s),and V_(p)/V_(s) structures of the mantle lithosphere beneath major cratons

Cratons formed due to the specific melting regime of the primitive mantle with elevated mantle temperature during Archean.However,each craton has undergone a distinct evolution history,and some have lost their stability.To investigate to what degree cratons in comparison with one another have been modified from their analogous initial form,we employed Sn-Pn differential(PSn) traveltimes to derive Vp/Vsratio,which is thought to be related to Mg# of the uppermantle.We assessed Pn,Sn,and PSn data using three datasets based on epicentral distance:(1) 2°–12°,(2) 2°–7°,and(3) 7°–12°.The results suggest that most cratons show comparable seismic properties with high velocities and low Vp/Vsratio,implying a highly depleted uppermost mantle that resembles the original residue from the partial melt extraction of the primitive mantle during the Archean.Conversely,the Eastern North China Craton(ENCC) displays the lowest P-and S-wave velocities,and noticeable high Vp/Vsratios in all datasets,implying a systematic difference with other cratons.This observation suggests a scenario of total removal of the depleted Archean mantle lithosphere beneath the ENCC.In contrast,the Ordos Block located at the western part of the North China Craton(WNCC) shows velocities and Vp/Vsratio comparable with those of the typical cratons,suggesting that it has still maintained its Archean mantle lithosphere.The Wyoming Craton has a high Vp/Vsratio similar to that of the ENCC and a high Pwave velocity comparable to that of the typical cratons.These features suggest that the Archean mantle lithosphere has been significantly modified rather than totally removed and replaced by a younger fertile mantle.The Indian Craton presents a low Vp/Vsratio and comparatively high velocities at shallow parts of the mantle lithosphere but a high Vp/Vsratio at deeper parts similar to that of the ENCC,suggesting a partial modification of the Indian Craton at deeper parts.

Investigating the relationship between crash severity,traffic barrier type,and vehicle type in crashes involving traffic barrier

Roadside safety is one of the important components of highway systems due to its considerable rate of high-severity crashes.Traffic barriers play a key role in reducing the crash severity and saving more lives on roadsides but choosing an inappropriate traffic barrier could decrease traffic barriers’efficiency.This paper investigated the variables affecting crash severity in different traffic barrier types(cable,guardrail,and rigid)and vehicle types(truck,and non-truck).For this purpose,an ordinal logistic regression approach was conducted on the crash data collected between 2007 and 2016 in Wyoming.According to the results,different traffic barrier types show different relationships to crash severity based on posted speed limit at the site.In guardrail segments,a high-severity crash is more likely when the posted speed limit is more than 55 mph;however,cable barrier crashes were less severe in high-speed limit(>55 mph)areas.While light vehicles were more vulnerable to crashes hitting rigid barriers,no significant difference was found between performances of cable and rigid barriers in terms of truck crash severity.The analytical models proposed in this study would make a clear view for designers and decision-makers in selecting the most appropriate traffic barrier.Also,the effective factors introduced in each model could be used to rank the risk posed by existing traffic barrier segments based on traffic barrier type,truck volume percentage,and other highway characteristics.