Introduction to Sight Distance

The results indicate that (1) distance risk perception, speed risk perception, and platoon risk status were well explanatory and predictive to vehicle crash risk variation and platoon crash risk variation; (2) the effects of reverse linear perspective as a visual cue on driving behaviors and crash risk variations in car-following were adequately quantified by its geometrical characteristics concerning distance perception; (3) the visual cue of reverse linear perspective in addition with initial distance, stopping sight distance, and the type of leading vehicles explained 33 % of the variance in distance risk perception; the temporal frequency, initial speed, and the type of following vehicles explained 23 % of the variance in speed risk perception; distance risk perception, speed risk perception, and platoon risk status combinedly explained 25 % and 22 % of the total variance in vehicle crash risk variation and platoon crash risk variation, respectively; (4) vehicle crash risk variation and platoon crash risk variation were equivalently specified by those observed explanatory factors.

A determination method and suggested value of a reasonable driving speed limit in dynamic low-visibility conditions were proposed based on the stopping sight distance model.

In the present research, Stopping Sight Distance (SSD) adequacy is assessed through a three-dimensional approach, which associates road visibility in terms of grade effect.

Safety barriers limit the severe consequences to occupants of vehicles leaving the roadway from colliding with obstacles, yet they may significantly reduce the available sight distance (ASD.

Radius of curve, length of curve, length of tangent section, superelevation at curves, degree of curvature, deflection angle and minimum available sight distance at curves were the geometric variables considered.

The study found that drivers tend to drive in the wrong direction as a result of driveways with a close median opening, poor front access control, lack of backage road connection, and limited sight distance because of large median widths or grade difference.

Results of logistic regression models revealed several influential factors on pedestrian fatalities and head injuries, including elderly pedestrians, male drivers, intoxicated drivers, rural roadways, unlit streets in darkness, limited sight distance, adverse weather conditions, midnight hours, and a heavy vehicle as the crash partner.

In view of the shortcomings of machine vision detection, such as lack of real-time, short sight distance and poor environmental adaptability, a railway foreign object detection method based on microwave radar is proposed.

Short sight distances at rural intersections can result in reduced safety including drivers choosing smaller gaps between oncoming vehicles (Yan & Richards, 2010).

The outcomes indicate that vehicle speed, lack of enforcement, absence of traffic signal (for traffic as well as pedestrians), land use type, slum population, inadequate sight distance, pedestrian's state of crossing, and pedestrian's risky crossing behaviour substantially affect the average PET at road network-level.

Based on the statistical assessment carried out in this study, there is evidence that factors such as road width, land use type, the absence of designated bus stop facility, inadequate sight distance, average daily traffic and pedestrian volume, and pedestrian–vehicular interaction considerably affect pedestrian safety at the intersections.

Reliability analysis has been advocated as a robust methodology to quantify the risk (known as the probability of non-compliance, Pnc) associated with design limitations such as insufficient sight distance on horizontal curves.

However, there are several main problems related to channelization design at intersections, including poor recognizability, unreasonable entering speed, insufficient sight distance, and relatively low merging speed.

97% in a certain sight distance.

97% in a certain sight distance.

One of their critical aspects is the passing sight distance (PSD), which is the minimum distance required for executing a safe passing maneuver using the opposing travel lane.

An essential component needed in the design of safe two-lane highways is the passing sight distance (PSD).