The goal of transportation is generally stated as the safe and efficient movement of people and goods. To achieve this goal, designers use many tools and techniques.
One technique used to improve safety on roadways is to examine the consistency of the design. Design consistency refers to highway geometry’s conformance with driver expectancy. Generally, drivers make fewer errors at geometric features that conform with their expectations.
Figure (3) – Speed Profile, main screen
An inconsistency in design can be described as a geometric feature or combination of features with unusual or extreme characteristics that drivers may drive in an unsafe manner. This situation could lead to speed errors, inappropriate driving maneuvers, and/or an undesirable level of accidents. This program provides an estimate of the expected 85th percentile speed profile of cars and trucks. It also provides an estimate of the design consistency.
It is intended to be used for preliminary highway planning and as an estimation model to identify inconsistencies in horizontal design of two-lane highways. It is not intended to be used as a speed limit determination tool.
Design Considerations
- Code optimizing : a long and complicated algorithms required an optimal code for decreasing calculations time and performances.
- Friendly Graphical User Interface: all user interaction are on one single screen, which divided to control panel and window display for the results.
