scholarly journals Acceleration and Deceleration Parameter Calibration of Tunnel Entrance Based on the Naturalistic Driving Test of Passenger Car

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Shijian He ◽  
Xinsha Fu ◽  
Zhihua Tan ◽  
Jijing Wang ◽  
Ting Ge

The precise calibration of acceleration and deceleration parameters is crucial for improving the accuracy of operating speed prediction and analysis tools at tunnel entrances. Therefore, acceleration and deceleration data of passenger car captured from 20 drivers at 30 tunnel entrances were collected from 200 m outside to 200 m inside the tunnel portal and averaged across four study zones. The results show that, first, the distribution of deceleration rates based on speed differs from that of acceleration rates based on speed in all zones. Second, significant differences in the probability density distribution of deceleration were found between each zone ( p < 0.001 ), but differences in acceleration could not be found between any zones ( p > 0.05 ). Third, the feature values (breakpoints) of the acceleration/deceleration cumulative frequency curves were located near the 95th percentile, differing from the traditional 85th percentile found with the extant model. The feature values of acceleration in the four zones coincided at 0.5 m/s2 and those of deceleration were 0.93, 0.85, 0.70, and 0.47 m/s2 under zones 1–4, respectively. This study provides accurate feature values of acceleration and deceleration for modelling an updated tunnel entrance operating speed prediction model.

2021 ◽  
Vol 17 ◽  
pp. 595-603
Author(s):  
Panagiotis Lemonakis ◽  
George Botzoris ◽  
Athanasios Galanis ◽  
Nikolaos Eliou

The development of operating speed models has been the subject of numerous research studies in the past. Most of them present models that aim to predict free-flow speed in conjunction with the road geometry at the curved road sections considering various geometric parameters e.g., radius, length, preceding tangent, deflection angle. The developed models seldomly take into account the operating speed profiles of motorcycle riders and hence no significant efforts have been put so far to associate the geometric characteristics of a road segment with the speed behavior of motorcycle riders. The dominance of 4-wheel vehicles on the road network led the researchers to focus explicitly on the development of speed prediction models for passenger cars, vans, pickups, and trucks. However, although the motorcycle fleet represents only a small proportion of the total traffic volume motorcycle riders are over-represented in traffic accidents especially those that occur on horizontal curves. Since operating speed has been thoroughly documented as the most significant precipitating factor of vehicular accidents, the study of motorcycle rider's speed behavior approaching horizontal curves is of paramount importance. The subject of the present paper is the development of speed prediction models for motorcycle riders traveling on two-lane rural roads. The model was the result of the execution of field measurements under naturalistic conditions with the use of an instrumented motorcycle conducted by experienced motorcycle riders under different lighting conditions. The implemented methodology to determine the most efficient model evaluates a series of road geometry parameters through a comprehensive literature review excluding those with an insignificant impact to the magnitude of the operating speeds in order to establish simple and handy models.


Author(s):  
Adrián Ricardo Archilla ◽  
Arístides Osvaldo Fernández de Cieza

Truck performance observed on grades on National Highway 7 in Argentina is described. The observed weight-to-power ratio distribution in Argentina is shown to be considerably higher than that in North America. Also, a speed prediction model based on the simple force balance equation is fitted to the field data. The model explains about 80 percent of the observed variation, and for steep upgrades the predictions are similar to values observed in the United States. Acceleration and deceleration performance curves are also given. Finally, a validation of the model is presented by comparing the predicted and the observed speed profiles along two upgrades for trucks of known weight-to-power ratios. The shapes of the speed profiles predicted by the model closely replicate the observed speed profiles.


Author(s):  
Kay Fitzpatrick ◽  
Jon M. Collins

Design consistency refers to highway geometry’s conformance with driver expectancy. Generally, drivers make fewer errors at geometric features that conform with their expectations. A proposed method for evaluating design consistency is to predict the speed along an alignment by using a speed-profile model. A speed-profile model was developed by using the following: speed prediction equations that calculate the expected speed at horizontal, vertical, or combination curves; assumed desired speed for the roadway; TWOPAS equations that determine the performance-limited speeds at every point; acceleration and deceleration rates; and several documented assumptions. The speed-profile model can be used to evaluate the design consistency of a facility or to generate a speed profile along an alignment. In conclusion, the speed-profile model developed appears to provide a suitable basis for the Interactive Highway Safety Design Model design consistency module.


Author(s):  
Alfonso Montella ◽  
Francesco Galante ◽  
Filomena Mauriello ◽  
Massimo Aria

To improve highway design consistency, several studies developed operating speed prediction models and investigated drivers' speed behavior. Most existing models are based on spot speed data that assume constant operating speed throughout the horizontal curves and occurrence of acceleration and deceleration only on tangents. To overcome limitations associated with existing models, this study investigated continuous speed profiles with an experiment that used a high-fidelity dynamic-driving simulator on a two-lane highway. A piecewise linear regression model and locally weighted regression scatter-plot smoothing were used to remove noise in the data set while preserving underlying patterns and to identify significant changes in the speed profile. Based on the smoothed speed profiles, models to predict operating speed in curves and in tangents, deceleration and acceleration rates to be used in the operating speed profiles, and starting and ending points of constant operating speed in curve were developed. Radius of the curve notably affected not only the operating speed in the curve but also the operating speed of the tangent following the curve: the smaller the radius, the lower the operating speed of the exit tangent. Both acceleration and deceleration rates increased with curvature. This study found that operating speed was not constant along curves. On small radius curves, deceleration ended close to the center of the curve, and acceleration starts, close to the end of the curve. Increasing the curve radius, the end point of deceleration moves toward the curve's beginning, whereas the start of acceleration moves toward the center of the curve.


Author(s):  
Daniel R. Jessen ◽  
Karen S. Schurr ◽  
Patrick T. McCoy ◽  
Geza Pesti ◽  
Ryan R. Huff

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