Empirical modeling of the relationship between decision sight distance and stopping sight distance based on AASHTO
Journal Title: Archives of Transport - Year 2018, Vol 4, Issue 48
Abstract
The paper introduces implementation of highways' stopping sight distance (SSD) and decision sight distance (DSD) based on AASHTO modeling assumptions. SSD characterizes the necessary distance for highway vehicles to stop safely in front from an obstacle. SSD is a function of vehicle speed, perception reaction time, deceleration rate, and grade based on AASHTO and most highway design international guidelines. The deceleration rate which is assumed constant (3.4 m/sec2) based on AASHTO 2011 is generally controlled by the friction coefficient depending on the road surface conditions. A driver's demanded deceleration rate may not exceed the range of friction coefficient according to various pavement conditions. Although SSD is generally sufficient to allow skilled and alert drivers to the stop their vehicles under regular situations, this distance is insufficient when information is difficult to comprehend. A DSD should be provided in highways geometric design when the driver is required to detect an unexpected or difficult to perceive information source. Interchanges (specifically exit ramps) and intersections, and required changing in driver direction of travel, changes in the basic cross section such as toll plaza, lane drop, are typical scenarios where driver needs DSD in the safety manner. The introduction of the two sight distance types (SSD and DSD) is a perquisite for empirical modeling of the relationship between DSD and SSD. The modeling refers to DSD for rural highways, suburban roads, and urban roads based on AASHTO models. Specifically the paper covers DSD three avoidance maneuver types of stopping (types A, A1, B) and three maneuver types of speed, path, and direction changing (types C,D, E) for the three roadway categories. The major parameters that control these avoidance types are pre-maneuver times, and pre-maneuver plus maneuver times. The empirical relationship proposed in this study simplifies the process of evaluating the decision sight distance based on stopping sight distance record, based on AASHTO models, without the need of strenuous estimation of the DSD model maneuver and deceleration parameters. Such a simplified correlation has not been found in the literature except a rough approximation documented in the British highway design guidelines.<br/><br/>
Authors and Affiliations
Shy BASSAN
Keywords
Related Articles
- EP ID EP431368
- DOI 10.5604/01.3001.0012.8362
- Views 123
- Downloads 0
INNOVATIVE RAIL FREIGHT WAGONS – A PRECONDITION TO INCREASE THE MARKET-SHARE OF RAIL FREIGHT
Rail transport is a very important type of transport. Due to its environmentally friendly nature it is necessary to dedication him considerable attention. The article stated the need for the implementation of innovative...
MATHEMATICAL MODELLING AND PARAMETERS CALCULATIONS IN MULTIMODAL FREIGHT TERMINAL NETWORKS
There are presented the mathematical models, routing algorithms and calculation algorithms for cargo flows in transport-terminal road-air-railways networks of multimodal transport operators<br/><br/>
MULTI-OBJECTIVE OPTIMIZATION APPLIED FOR PLANNING OF REGIONAL EUROPEAN AIRLINE
Fleet planning is very important elements in the airlines planning process. Fleet planning should answer the question which types of aircraft are required and how many of them are required taking into account the current...
Design of brake force distribution model for front-and-rear-motor-drive electric vehicle based on radial basis function
To achieve high-efficiency and stable brake of a front-and-rear-motor-drive electric vehicle (FRMDEV) with parallel cooperative braking system, a multi-objective optimal model for brake force distribution is created base...
Using the Petri nets for forming the technological lines of the passenger trains processing in Ukraine
Despite the large number of publications, which authors use the mathematical apparatus of Petri nets for the transportation systems studies, there are still no such researches of technological processing lines for passen...