Transcript Safety Management Identification of Hazardous Locations by

Highways and Highway Components
Highway Transportation Characteristics
Outline
Functional classification of roads
Road functions
Hierarchical structure of road networks
Mobility vs. accessibility
Mobility vs. transportation mode
Highway components
Cross-sections
Highway plan and profile
Interchanges
Rural and urban intersections
Road
Functions
Mobility
Accessibility
Hierarchical
Structure of
Road
Networks
Rural
Urban
Mobility vs. Accessibility
Road Class
Road Function
Freeways
Through movement exclusively
Surface Arterials
Through movement primary and
some land access
Collectors
Local Roads
Traffic movement to higher rank
roads, access to abutting properties
Access to abutting land and local
traffic movement
Hierarchical
Structure of
Road
Networks
Mobility vs.
Accessibility
Mobility vs. Transportation Mode
Mobility vs. Transportation Mode
Capacity
capacity in veh/h =
capacity in veh/h/lane x number of lanes
capacity in persons/h =
capacity in veh/h x average vehicle occupancy
Mobility vs. Transportation Mode
Capacity
Facility
Three-lane urban freeway
Three-lane urban arterial
One lane of buses
Vehicles/hr
Persons/hr
2,000 x 3 = 6,000
6,000 x 1.7 = 10,200
800 x 3 = 2,400
2,400 x 1.7 = 4,080
100 x 1 =100
100 x 80 = 8,000
One track of light rail
19,000
One track of heavy rail
40,000
Mobility vs. Transportation Mode
Capacity
Highway
Components
Cross-section
Highway Components
Highway plan and profile
Highway
Components
Urban Intersections
Picture
Highway
Components
Rural Intersections
Picture
Highway
Components
Interchanges
Diamond
Cloverleave
Urban directional