Design Speed and Operating Speed in Rural Highway Alignment Design

2000 ◽  
Vol 1701 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Raymond A. Krammes
Keyword(s):  
Empirical Evidence ◽  
Operating Speed ◽  
Current Policy ◽  
Design Speed ◽  
Rural Highway ◽  
Highway Alignment ◽  
The Relationship

The relationship between design speeds and operating speeds on twolane rural highway alignments is evaluated. The current policy on design speed and its origins is described, and empirical evidence of disparities between design speeds and operating speeds are presented. U.S. policy on selecting and applying design speeds is critiqued, modifications to the design-speed concept in Australia and Europe are discussed, and possible revisions to U.S. policy on design speed are identified.

Operating Speed on Crest Vertical Curves with Limited Stopping Sight Distance

2000 ◽  
Vol 1701 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Daniel B. Fambro ◽  
Kay Fitzpatrick ◽  
Charles W. Russell
Keyword(s):  
Operating Speed ◽  
Design Elements ◽  
Geometric Data ◽  
A Value ◽  
Sight Distance ◽  
The Mean ◽  
The Difference ◽  
Design Speed ◽  
Stopping Sight Distance ◽  
The Relationship

Horizontal and vertical elements of a highway are designed based on an assumed design speed. This concept was developed in the 1930s as a mechanism for designing rural alignments to permit most drivers to operate uniformly at their desired speed. In 1938, AASHO recognized that drivers select a speed influenced by the roadway environment instead of an assumed design speed. Recent research suggests that design speed is no longer the speed adopted by the faster group of drivers but that it has become a value used to establish the sharpness of horizontal and vertical design elements. The objective of this study was to establish the relationship between design and operating speeds for crest vertical curves with limited sight distance. Geometric data and 3,500 paired speeds (speeds at control and crest sections) were collected at 36 sites in 3 states. The results indicated that both the 85th percentile and the mean operating speeds were well above the inferred design speeds of the crest vertical curves for the range of conditions studied and that the lower the design speed the larger the difference between the 85th percentile speed and the design speed. The mean reductions in speed between the control and crest sections tend to increase as available sight distance is decreased; however, the reduction in speed is less than that suggested by current AASHTO criteria.

scholarly journals Research on the Safety Audit Methods for Two-Lane Highway Based on HRV

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Zhan-dong Zhu ◽  
Ying-chih Lu ◽  
Cheng-hong Fu ◽  
Ting Xu
Keyword(s):  
Velocity Gradient ◽  
Road Safety ◽  
Evaluation Criteria ◽  
Safety Evaluation ◽  
Operating Speed ◽  
Acceleration Rate ◽  
Design Speed ◽  
Route Safety ◽  
The Relationship ◽  
Speed Gradient

In order to explore stable route safety evaluation indicators, this study discusses the relationship between the heart rate variability (HRV) and other factors, such as design speed, operating speed, acceleration rate, and velocity gradient through a lot of experiments. The results show that operating speed coordination and velocity gradient (Gv) outperform others as road safety indicators. Speed coordination evaluation criteria:|ΔV85|≤10 km/h, good coordination; 10 km/h≤|ΔV85|≤ 20 km/h, general coordination, route indicators of adjacent sections should be adjusted, so that the speed difference is not more than 10 km/h;|ΔV85|≥20 km/h, poor speed coordination, it needs to readjust the design of the adjacent sections. Speed gradient evaluation criteria:Gv≤0.10, good road safety;0.10≤Gv<0.15, common road safety;Gv>0.15, poor road safety and the adjacent sections need to readjust. The conclusions provide the theoretical reference for highway safety evaluation.

Spotting a liar by looking for microexpressions: Challenges and Opportunities

2019 ◽  
Author(s):  
Xunbing Shen
Keyword(s):  
Empirical Evidence ◽  
Deception Detection ◽  
Empirical Studies ◽  
High Stake ◽  
Challenges And Opportunities ◽  
Cues To Deception ◽  
The Relationship

Microexpressions do exist, and they are regarded as valid cues to deception by many researchers, furthermore, there is a lot of empirical evidence which substantiates this claim. However, some researchers don’t think the microexpression can be a way to catch a liar. The author elucidates the theories predicting that looking for microexpressions can be a way to catch a liar, and notes that some data can support for the utilization of microexpressions as a good way to detect deception. In addition, the author thinks that the mixed results in the area of investigating microexpressions and deception detection may be moderated by the stake. More empirical studies which employ high-stake lies to explore the relationship between microexpressions and deception detection are needed.

Perspectives

2017 ◽  
Author(s):  
Armin Schnider
Keyword(s):  
Experimental Investigation ◽  
Experimental Evidence ◽  
Empirical Evidence ◽  
False Memories ◽  
Experimental Basis ◽  
The Relationship ◽  
Scientific Standards

This chapter summarizes current interpretations of all forms of confabulations discussed in the book and reviews the relationship between the four forms of memory-related confabulations. Experimental investigation has confirmed the dissociation between various types of false memories and considerably advanced the understanding of the mechanisms of some forms of confabulation, in particular behaviourally spontaneous confabulation and false statements in anosognosia. Overall, experimental evidence is scarce; many models have no controlled experimental basis or extend their proposed range of application well beyond the empirical evidence. The chapter concludes with a call for heightened respect of basic scientific standards in the research on confabulation.

Traffic and speed characteristics on two-lane highways: field study

2003 ◽  
Vol 30 (6) ◽  
pp. 1042-1054 ◽  
Author(s):  
Yasser Hassan
Keyword(s):  
Light Condition ◽  
Operating Speed ◽  
Ambient Light ◽  
Horizontal Curve ◽  
Vehicle Class ◽  
Rural Highways ◽  
Horizontal Alignment ◽  
Heavy Truck ◽  
Traffic Composition ◽  
Rural Highway

Many models have been developed to evaluate the operating speeds on two-lane rural highways. However, provided information usually lacks details essential to assess their applicability at locations other than where they were developed. This paper presents a procedure to interpret raw data collected on three horizontal curve sites of different two-lane rural highway classes in Ontario. The speed observations were categorized into three vehicle classes (passenger car, light truck, and multi-axle heavy truck) and four light condition categories (day, night, and two transition periods). The minimum headway and percentile value to define the operating speed were examined, and a revision of the current practice deemed not warranted. The findings also indicated that operating speeds do not depend on the time or vehicle class. Finally, the horizontal alignment affects the operating speed, but the speeds of the two travel directions on a horizontal curve may differ even with little contribution of the vertical alignment.Key words: highway geometric design, operating speed, traffic composition, traffic counters, ambient light, acceleration, deceleration.

scholarly journals The Relationship between Risk and Return - An Empirical Evidence from Real Estate Stocks Listed in Vietnam

2019 ◽  
Vol 9 (11) ◽  
pp. 1211-1226
Author(s):  
Phan Tran Minh Hung ◽  
Tran Thi Trang Dai ◽  
Phan Nguyen Bao Quynh ◽  
Le Duc Toan ◽  
Vo Hoang Diem Trinh
Keyword(s):  
Real Estate ◽  
Empirical Evidence ◽  
Risk And Return ◽  
The Relationship

Turnout and the Vote: The Joke's on the Democrats

1980 ◽  
Vol 74 (2) ◽  
pp. 406-420 ◽  
Author(s):  
James DeNardo
Keyword(s):  
Empirical Evidence ◽  
Common Sense ◽  
Majority Party ◽  
Conventional View ◽  
Theoretical Reasoning ◽  
The Relationship

A heavy turnout is commonly believed to favor the Democrats. This study presents theoretical reasoning and empirical evidence that challenge the conventional view. Reasonable assumptions about the behavior of core and peripheral voters lead to the conclusion that the majority party is most likely to suffer when turnout increases, common sense notwithstanding. It also appears that the recent decay of partisan loyalties among voters has eroded the relationship between turnout and the vote.

Sign in / Sign up

Export Citation Format

Share Document