PPT: Highway Geometric Design | Transportation Engineering - Civil Engineering (CE) PDF Download

 Page 1


Definition of Geometric Design :
? Geometric design of highways deals with the dimensions and layout of 
visible features of the highway. 
? Geometric design fulfills the requirements of the driver and the vehicle, 
such as comfort, efficiency and safety.
? Proper geometric design will help in the reduction of accidents and their 
severity.
Page 2


Definition of Geometric Design :
? Geometric design of highways deals with the dimensions and layout of 
visible features of the highway. 
? Geometric design fulfills the requirements of the driver and the vehicle, 
such as comfort, efficiency and safety.
? Proper geometric design will help in the reduction of accidents and their 
severity.
Goals of Geometric design :
? Maximize the comfort, safety and economy of facilities.
? Provide efficiency in traffic operation.
? Provide maximum safety at reasonable cost.
? Minimize the environmental impacts.
Page 3


Definition of Geometric Design :
? Geometric design of highways deals with the dimensions and layout of 
visible features of the highway. 
? Geometric design fulfills the requirements of the driver and the vehicle, 
such as comfort, efficiency and safety.
? Proper geometric design will help in the reduction of accidents and their 
severity.
Goals of Geometric design :
? Maximize the comfort, safety and economy of facilities.
? Provide efficiency in traffic operation.
? Provide maximum safety at reasonable cost.
? Minimize the environmental impacts.
Factors affecting geometric design :
? Design speed.
? Topography.
? Traffic.
? Environmental factors.
? Economical factors.
? Vehicles properties (dimensions, weight, operating characteristics, etc.).
? Humans (the physical, mental and psychological characteristics of the driver and 
pedestrians like the reaction time).
Page 4


Definition of Geometric Design :
? Geometric design of highways deals with the dimensions and layout of 
visible features of the highway. 
? Geometric design fulfills the requirements of the driver and the vehicle, 
such as comfort, efficiency and safety.
? Proper geometric design will help in the reduction of accidents and their 
severity.
Goals of Geometric design :
? Maximize the comfort, safety and economy of facilities.
? Provide efficiency in traffic operation.
? Provide maximum safety at reasonable cost.
? Minimize the environmental impacts.
Factors affecting geometric design :
? Design speed.
? Topography.
? Traffic.
? Environmental factors.
? Economical factors.
? Vehicles properties (dimensions, weight, operating characteristics, etc.).
? Humans (the physical, mental and psychological characteristics of the driver and 
pedestrians like the reaction time).
Road alignment :
Alignment : is an arrangement in a straight line or in correct relative 
positions.
? The position or the layout of the central line of the highway on the 
ground is called the alignment.
? Horizontal alignment includes straight and curved paths. 
? Vertical alignment includes level and gradients.
Page 5


Definition of Geometric Design :
? Geometric design of highways deals with the dimensions and layout of 
visible features of the highway. 
? Geometric design fulfills the requirements of the driver and the vehicle, 
such as comfort, efficiency and safety.
? Proper geometric design will help in the reduction of accidents and their 
severity.
Goals of Geometric design :
? Maximize the comfort, safety and economy of facilities.
? Provide efficiency in traffic operation.
? Provide maximum safety at reasonable cost.
? Minimize the environmental impacts.
Factors affecting geometric design :
? Design speed.
? Topography.
? Traffic.
? Environmental factors.
? Economical factors.
? Vehicles properties (dimensions, weight, operating characteristics, etc.).
? Humans (the physical, mental and psychological characteristics of the driver and 
pedestrians like the reaction time).
Road alignment :
Alignment : is an arrangement in a straight line or in correct relative 
positions.
? The position or the layout of the central line of the highway on the 
ground is called the alignment.
? Horizontal alignment includes straight and curved paths. 
? Vertical alignment includes level and gradients.
Alignment decision is important because a bad alignment will enhance 
the construction, maintenance and vehicle operating cost. Once an 
alignment is fixed and constructed, it is not easy to change it due to 
increase in cost of adjoining land and construction of costly structures 
by the roadside.