Exploring Vehicle Probe Data as a Resource to Enhance Network-Wide Traffic Volume Estimates

2021 ◽  
Author(s):  
Giuseppe Grande ◽  
Matthew Lesniak ◽  
Louis-Paul Tardif ◽  
Jonathan D Regehr
Keyword(s):  
Travel Speed ◽  
Traffic Monitoring ◽  
Flow Speed ◽  
Traffic Volume ◽  
Volume Data ◽  
Annual Average Daily Traffic ◽  
Traffic Volumes ◽  
The Mean ◽  
Volume Estimates ◽  
Potential Use

Annual average daily traffic (AADT) is a fundamental input for numerous civil engineering applications, yet generating reliable estimates of AADT at a network-wide level poses challenges. This article explores the potential use of vehicle probe data to enhance conventional traffic monitoring practice for generating network-wide estimates of AADT by exploring relationships between site-specific traffic volume data and vehicle probe data collected in Manitoba, Canada. The analysis revealed that mean travel speed cannot be used to predict traffic volumes on Manitoba highways, since the mean travel speed did not deviate from the free-flow speed regardless of the volume measured. The quantity of probe data observations showed moderate correlation with traffic volume at some sites (R-squared up to 0.65), but these correlations were stronger (R-squared up to 0.9) when considering trucks only. These findings suggest that probe data could be used to estimate truck volumes at certain locations.

Consistency of Interchange Outer Connection Ramps

2020 ◽  
Author(s):  
H.R. Al-Masaeid ◽  
Tareq M. Magsi ◽  
Hatem H. Almasaeid
Keyword(s):  
Traffic Accidents ◽  
Deflection Angle ◽  
Flow Speed ◽  
Traffic Volume ◽  
Free Flow ◽  
Operating Speed ◽  
Speed Reduction ◽  
Free Flow Speed ◽  
Traffic Volumes ◽  
Geometric Variables

Interchange ramps need a proper and consistent geometric design to avoid possible traffic accidents. The objective of this study is to develop guidelines for consistent design of outer connection ramps. As such, 47 ramps were selected from18 different interchanges in Jordan. Free-flow speed measurements, for different vehicle classes, were taken along ramps and at predefined points. Also, traffic accidents, geometric variables, and traffic volumes were obtained. For circular ramps, the analysis indicated that the operating speed reduction is strongly affected by radius and deflection angle of the curve. The radius of the first curve had the greatest impact on speed reduction on curve-straight-curve ramps. For reverse-curve ramps, the ratio of the radii should be 6:4:9 to achieve a good consistent design for cars, provided that the radius of the first curve exceeds 110 m. Further analysis indicated that speed reduction, geometric variables, and traffic volume are influenced the accident occurrences.

scholarly journals Constructing a Network Fundamental Diagram: Synthetic Origin–Destination Approach

2019 ◽  
Vol 2673 (7) ◽  
pp. 479-488 ◽  
Author(s):  
Jianhe Du ◽  
Hesham A. Rakha
Keyword(s):  
Data Collection ◽  
Large Scale ◽  
Traffic Monitoring ◽  
Traffic Volume ◽  
Network Control ◽  
Volume Data ◽  
Monitoring And Control ◽  
Fundamental Diagram ◽  
Probe Vehicle ◽  
Network Fundamental Diagram

The network fundamental diagram (NFD) is increasingly used in traffic monitoring and control. One obstacle to a wider application of NFDs in network control is the difficulty of obtaining data from all vehicles traveling in the network to construct an accurate NFD. One solution is to estimate the NFD using data from only a fraction of vehicles (i.e., probe vehicles), where the probe vehicle market penetration rate (MPR) needs to be estimated. A previous study conducted by the authors demonstrated that a distance or time-weighted harmonic mean was needed to estimate the flow- and density-based MPRs, respectively, using a pairing k-mean clustering approach. This paper proposes another approach that utilizes probe vehicle and observed link volume data to estimate the MPR. A heuristic model is proposed to identify the optimum locations from which to collect link traffic volume data for use in the MPR estimation. The estimated MPR can then be used to construct the NFD. Results show that these models can accurately estimate the NFD with limited probe vehicle and link traffic volume data. Accordingly, the models can be used in the field to estimate the NFD using readily available loop detector and probe vehicle data. The ideal locations for traffic volume data collection can also be proactively chosen to generate optimum estimation results. As the models proposed here show no significant gains with an increased magnitude of collected data after a certain threshold, they will be helpful, particularly when large-scale data collection is not affordable or realistic.

Investigating Total Annual Average Daily Traffic as a Surrogate for Motorcycle Volumes in Estimating Safety Performance Functions for Motorcycle Crashes

2017 ◽  
Vol 2637 (1) ◽  
pp. 9-16
Author(s):  
Craig Lyon ◽  
Bhagwant Persaud ◽  
Scott Himes
Keyword(s):  
Safety Management ◽  
Safety Performance ◽  
Volume Data ◽  
Annual Average ◽  
Annual Average Daily Traffic ◽  
Safety Performance Functions ◽  
Traffic Volumes ◽  
Crash Modification Factors ◽  
Crash Types ◽  
Motorcycle Crashes

Data on traffic volumes are required to estimate the safety performance functions (SPFs) used to develop crash modification factors and for various safety management applications. Estimation of SPFs for motorcycle crashes can be especially challenging because few jurisdictions collect motorcycle traffic volume data systematically. To address this challenge, analyses with data from Florida, Pennsylvania, and Virginia were conducted to explore how much predictive power for an SPF was lost when motorcycle traffic volumes were not known. The results of the analyses showed that when motorcycle volumes were unknown, the use of total annual average daily traffic on its own was sufficient to develop motorcycle crash SPFs. The potential bias from missing motorcycle-specific annual average daily traffic was sufficiently negligible where it existed, not to preclude SPF development. A more significant issue in the development of motorcycle crash SPFs is to work with a crash type that is relatively rare, so that SPFs cannot be developed for all motorcycle crash types or site types.

Analisis Kinerja dan Pengaruh Pelebaran Jalan serta Pembuatan Median Jalan (Studi Kasus Jalan Temanggung Tilung Kota Palangkaraya)

2018 ◽  
Vol 7 (1) ◽  
pp. 51-60
Author(s):  
Fitri Wulandari ◽  
Nirwana Puspasari ◽  
Noviyanthy Handayani
Keyword(s):  
Data Retrieval ◽  
Service Level ◽  
Traffic Volume ◽  
Primary Data ◽  
Volume Data ◽  
Saturation Degree ◽  
The Road ◽  
Before And After ◽  
Road Widening ◽  
The Way

Jalan Temanggung Tilung is a 2/2 UD type road (two undirected two-way lanes) with a road width of 5.5 meters, which is a connecting road between two major roads, namely the RTA road. Milono and the path of G. Obos. Over time, the volume of traffic through these roads increases every year, plus roadside activities that also increase cause congestion at several points of the way. To overcome this problem, the local government carried out road widening to increase the capacity and level of road services. The study was conducted to determine the amount of traffic volume, performance, service level of the Temanggung Tilung road section at peak traffic hours before and after road widening. Data retrieval is done by the direct survey to the field to obtain primary data in the form of geometric road data, two-way traffic volume data, and side obstacle data. Performance analysis refers to the 1997 Indonesian Road Capacity Manual (MKJI) for urban roads. From the results of data processing, before increasing the road (Type 2/2 UD), the traffic volume that passes through the path is 842 pcs/hour and after road widening (Type 4/2 UD) the traffic volume for two directions is 973 pcs/hour, with route A equaling 528 pcs/hour and direction B equaling 445 pcs/hour. Based on the analysis of road performance before road enhancement, the capacity = 2551 pcs/hour, saturation degree = 0.331, and the service level of the two-way road are level B. Based on the analysis of the performance of the way after increasing the way, the direction capacity A = 2686 pcs/hour and direction B = 2674 pcs /hour, saturation degree for direction A = 0.196 and direction B = 0.166, service level for road direction A and direction B increase to level A

scholarly journals Extracting Road Traffic Volume in the City before and during covid-19 through Video Remote Sensing

2021 ◽  
Vol 13 (12) ◽  
pp. 2329
Author(s):  
Elżbieta Macioszek ◽  
Agata Kurek
Keyword(s):  
Travel Behavior ◽  
Traffic Management ◽  
Road Traffic ◽  
Traffic Volume ◽  
The Road ◽  
Traffic Characteristics ◽  
Annual Average Daily Traffic ◽  
On The Road ◽  
The Impact ◽  
The City

Continuous, automatic measurements of road traffic volume allow the obtaining of information on daily, weekly or seasonal fluctuations in road traffic volume. They are the basis for calculating the annual average daily traffic volume, obtaining information about the relevant traffic volume, or calculating indicators for converting traffic volume from short-term measurements to average daily traffic volume. The covid-19 pandemic has contributed to extensive social and economic anomalies worldwide. In addition to the health consequences, the impact on travel behavior on the transport network was also sudden, extensive, and unpredictable. Changes in the transport behavior resulted in different values of traffic volume on the road and street network than before. The article presents road traffic volume analysis in the city before and during the restrictions related to covid-19. Selected traffic characteristics were compared for 2019 and 2020. This analysis made it possible to characterize the daily, weekly and annual variability of traffic volume in 2019 and 2020. Moreover, the article attempts to estimate daily traffic patterns at particular stages of the pandemic. These types of patterns were also constructed for the weeks in 2019 corresponding to these stages of the pandemic. Daily traffic volume distributions in 2020 were compared with the corresponding ones in 2019. The obtained results may be useful in terms of planning operational and strategic activities in the field of traffic management in the city and management in subsequent stages of a pandemic or subsequent pandemics.

scholarly journals The Recreational Trail of the El Caminito del Rey Natural Tourist Attraction, Spain: Determination of Hikers’ Flow

2021 ◽  
Vol 18 (4) ◽  
pp. 1809
Author(s):  
Gemma María Gea-García ◽  
Carmelo Fernández-Vicente ◽  
Francisco J. Barón-López ◽  
Jesús Miranda-Páez
Keyword(s):  
Eye Tracking ◽  
Circulation Pattern ◽  
Travel Speed ◽  
Outdoor Activity ◽  
Efficient Management ◽  
Exponential Increase ◽  
The Mean ◽  
Tracking Device ◽  
Tracking Devices

Hiking is a very popular outdoor activity, and has led to an exponential increase in the number of visitors to natural spaces. The objective of this study was to analyze the circulation pattern of visitors to the Caminito del Rey trail, based on the three zones into which the trail can be divided. The sample consisted of 1582 hikers distributed into three different profiles. Of these, 126 utilized an eye-tracking device during the hike, while, for the rest (1456), only their travel speed along the trail was recorded. The use of eye tracking devices identified a greater number of interesting landscapes located in zones 1 and 3 of the trail, and it was observed that the mean travel speed was greater for zone 2 (42.31 m/min) (p < 0.01). Additionally, when the three different visitor profiles were analyzed, significant differences were found between the mean travel speeds according to sectors (p < 0.05). This information is crucial for more efficient management of the trail, as it allows for the development of measures to control and regulate the flow of visitors according to zone, and the design of additional strategies to increase the awareness of the hiker about specific areas of the hike.

Volumetric quantification of aneurysmal subarachnoid hemorrhage independently predicts hydrocephalus and seizures

2021 ◽  
pp. 1-9
Author(s):  
Badih J. Daou ◽  
Siri Sahib S. Khalsa ◽  
Sharath Kumar Anand ◽  
Craig A. Williamson ◽  
Noah S. Cutler ◽  
...  
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Characteristic Curve ◽  
Volumetric Analysis ◽  
Aneurysm Rupture ◽  
Mean Difference ◽  
Analysis Tool ◽  
Volume Data ◽  
Hemorrhage Volume ◽  
The Mean

OBJECTIVEHydrocephalus and seizures greatly impact outcomes of patients with aneurysmal subarachnoid hemorrhage (aSAH); however, reliable tools to predict these outcomes are lacking. The authors used a volumetric quantitative analysis tool to evaluate the association of total aSAH volume with the outcomes of shunt-dependent hydrocephalus and seizures.METHODSTotal hemorrhage volume following aneurysm rupture was retrospectively analyzed on presentation CT imaging using a custom semiautomated computer program developed in MATLAB that employs intensity-based k-means clustering to automatically separate blood voxels from other tissues. Volume data were added to a prospectively maintained aSAH database. The association of hemorrhage volume with shunted hydrocephalus and seizures was evaluated through logistic regression analysis and the diagnostic accuracy through analysis of the area under the receiver operating characteristic curve (AUC).RESULTSThe study population comprised 288 consecutive patients with aSAH. The mean total hemorrhage volume was 74.9 ml. Thirty-eight patients (13.2%) developed seizures. The mean hemorrhage volume in patients who developed seizures was significantly higher than that in patients with no seizures (mean difference 17.3 ml, p = 0.01). In multivariate analysis, larger hemorrhage volume on initial CT scan and hemorrhage volume > 50 ml (OR 2.81, p = 0.047, 95% CI 1.03–7.80) were predictive of seizures. Forty-eight patients (17%) developed shunt-dependent hydrocephalus. The mean hemorrhage volume in patients who developed shunt-dependent hydrocephalus was significantly higher than that in patients who did not (mean difference 17.2 ml, p = 0.006). Larger hemorrhage volume and hemorrhage volume > 50 ml (OR 2.45, p = 0.03, 95% CI 1.08–5.54) were predictive of shunt-dependent hydrocephalus. Hemorrhage volume had adequate discrimination for the development of seizures (AUC 0.635) and shunted hydrocephalus (AUC 0.629).CONCLUSIONSHemorrhage volume is an independent predictor of seizures and shunt-dependent hydrocephalus in patients with aSAH. Further evaluation of aSAH quantitative volumetric analysis may complement existing scales used in clinical practice and assist in patient prognostication and management.

Neonatal Polycythemia: II. Plasma, Blood, and Red Cell Volume Estimates in Relation to Hematocrit Levels and Quality of Intrauterine Growth

PEDIATRICS ◽  
1981 ◽  
Vol 68 (2) ◽  
pp. 175-182
Author(s):  
Yves W. Brans ◽  
Donna L. Shannon ◽  
Rajam S. Ramamurthy
Keyword(s):  
Birth Weight ◽  
Exchange Transfusion ◽  
Intrauterine Growth Retardation ◽  
Umbilical Vein ◽  
Normal Growth ◽  
Red Cell ◽  
Intrauterine Growth ◽  
The Mean ◽  
Volume Estimates

Volumes of plasma (PV), blood (BV), and red cells (RCV) were estimated within 32 hours of birth in 39 neonates with normal growth, 14 neonates with intrauterine growth retardation, and 20 neonates with macrosomia. Total PV, BV, and RCV increased linearly with birth weight and were unaffected by deviation in the quality of fetal growth. In proportion to body weight, PV/kg, BV/kg, and RCV/kg correlated neither with birth weight nor with the quality of intrauterine growth. Neonates with umbilical vein hematocrit (UV Hct) levels 51% to 60%, 61% to 65%, and 66% to 77% had progressively lower, but not statistically different, mean PV/kg (38.1 ± 4.49, 37.6 ± 5.41, and 34.8 ± 5.16 ml/kg, respectively). On the other hand, they had progressively higher mean BV/kg (90 ± 10.1 vs 101 ± 13.7 ml/kg, P &lt; .002, and vs 110 ± 19.0 ml/kg, P &lt; .001). They also had progressively higher mean RCV/kg (52 ± 7.4, 64 ± 8.7, and 75 ± 16.4 ml/kg, P &lt; .001). Although PV/kg did not correlate with UV Hct, both BV/kg and RCV/kg increased linearly with increasing UV Hct (r = .58 and r = .79, respectively). Volume estimates were repeated after partial exchange transfusion in 29 neonates. Mean UV Hct decreased from 63 ± 5.9% preexchange to 51 ± 5.2% postexchange (P &lt; .001), mean PV increased from 37.7 ± 5.56 to 47.6 ± 7.99 ml/kg (P &lt; .001) and mean RCV decreased from 67 ± 16.5 to 51 ± 12.3 ml/kg (P &lt; .001). Despite precautions to keep the partial exchange isovolemic, mean BV decreased from 105 ± 18.7 to 98 ± 18.0 ml/kg (P = .001) and the mean PV increase (10 ml/kg) was less than the mean RCV decrease (16 ml/kg). These data suggest that neonates with polycythemia have normal PV but their RCV and BV are elevated in direct proportion to UV Hct. "Isovolemic" partial exchange transfusion decreases UV Hct, RCV, and BV and increases PV.

Analysis of Red Cell Mass and Plasma Volume in Patients With Polycythemia

2005 ◽  
Vol 129 (1) ◽  
pp. 89-91 ◽  
Author(s):  
Mordechai Lorberboym ◽  
Naomi Rahimi-Levene ◽  
Helena Lipszyc ◽  
Chun K. Kim
Keyword(s):  
Body Weight ◽  
Plasma Volume ◽  
Cell Mass ◽  
Mean Value ◽  
Whole Body ◽  
Red Cell ◽  
Volume Data ◽  
Red Cell Mass ◽  
The Mean ◽  
Iodine 125

Abstract Context.—Polycythemia describes an increased proportion of red blood cells in the peripheral blood. In absolute polycythemia, there is increased red cell mass (RCM) with normal plasma volume, in contrast with apparent polycythemia, in which there is increased or normal RCM and decreased plasma volume. In order to deliver the appropriate treatment it is necessary to differentiate between the two. Objective.—A retrospective analysis of RCM and plasma volume data are presented, with special attention to different methods of RCM interpretation. Design.—The measurements of RCM and plasma volume in 64 patients were compared with the venous and whole-body packed cell volume, and the incidence of absolute and apparent polycythemia was determined for increasing hematocrit levels. Measurements of RCM and plasma volume were performed using chromium 51–labeled red cells and iodine 125–labeled albumin, respectively. The measured RCM of each patient was expressed as a percentage of the mean expected RCM and was also defined as being within or outside the range of 2 SD of the mean. The results were also expressed in the traditional manner of mL/kg body weight. Results.—Twenty-one patients (13 women and 8 men) had absolute polycythemia. None of them had an increased plasma volume beyond 2 SD of the mean. When expressed according to the criteria of mL/kg body weight, 17 of the 21 patients had abnormally increased RCM, but 4 patients (19%) had a normal RCM value. Twenty-eight patients had apparent polycythemia. The remaining 15 patients had normal RCM and plasma volume. Conclusions.—The measurement of RCM and plasma volume is a simple and necessary procedure in the evaluation of polycythemia. In obese patients, the expression of RCM in mL/kg body weight lacks precision, considering that adipose tissue is hypovascular. The results of RCM are best described as being within or beyond 2 SD of the mean value.

Prediction of Design Hourly Volume on Rural Roads

2020 ◽  
pp. 036119812096556
Author(s):  
Miloš Petković ◽  
Vladan Tubić ◽  
Nemanja Stepanović
Keyword(s):  
Coefficient Of Determination ◽  
Rural Roads ◽  
The Road ◽  
Annual Average Daily Traffic ◽  
Proposed Model ◽  
Traffic Volumes ◽  
Implementation Costs ◽  
On The Road ◽  
Predicted Values ◽  
Design Hourly Volume

Design hourly volume (DHV) represents one of the most significant parameters in the procedures of developing and evaluating road designs. DHV values can be accurately and precisely calculated only on the road sections with the implemented automatic traffic counters (ATCs) which constantly monitor the traffic volume. Unfortunately, many road sections do not contain ATCs primarily because of the implementation costs. Consequently, for many years, the DHV values have been defined on the basis of occasional counting and the factors related to traffic flow variability over time. However, it has been determined that this approach has significant limitations and that the predicted values considerably deviate from the actual values. Therefore, the main objective of this paper is to develop a model which will enable DHV prediction on rural roads in cases of insufficient data. The suggested model is based on the correlation between DHVs and the parameters defining the characteristics of traffic flows, that is, the relationship between the traffic volumes on design working days and non-working days, and annual average daily traffic. The results of the conducted research indicate that the application of the proposed model enables the prediction of DHV values with a significant level of data accuracy and reliability. The coefficient of determination (R2) shows that more than 98% of the variance of the calculated DHVs was explained by the observed DHV values, while the mean error ranged from 4.86% to 7.84% depending on the number of hours for which DHV was predicted.

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