Design Criteria CTC 440

Objectives Know what “design criteria” means Determine design criteria for various types of facilities

Design Criteria Project Specific Listing of the Standards for Critical Design Elements Provides the minimum standards normally used Values greater than the minimum standard should be used when feasible Must justify features if design criteria cannot be met

Influenced by: Functional Classification of Highway Traffic Volumes Operating Speed Terrain Project Type

2.2 Project Types (4) Reconstruction / New Construction Work to replace an existing highway, including any necessary geometric improvements Resurfacing, Restoration & Rehabilitation (3R) on Interstates and Freeways Work is generally limited to pavement resurfacing, restoration, or rehabilitation Intersection Reconstruction Work consists of operational improvements at one or more intersections (turn lanes and widenings, improvements such as signs, lighting, drainage improvements, installation of signals, channelization, and/or pavement markings) Bridge Projects Purpose of project is to construct a new bridge or to replace or rehabilitate an existing bridge. Incidental work on the approaches may be included.

2.3 Design Criteria Sources A Policy on Geometric Design of Highways and Streets (2001) A Policy on Design Standards, Interstate System (2002 Draft) NYSDOT Bridge Manual Guidelines for Highways within the Adirondack Park (1996) Americans with Disabilities Act Accessibility Guidelines (ADAAG) National Cooperative Highway Research Program (NCHRP)

2.4 Functional Classification of Highways Different roadways have different functions Freeways move high traffic volumes at high speeds w/ limited local access Local roads sacrifice high speed and volume for increased local access Arterials & collectors provide intermediate service between these two extremes Urban and rural roadways are very different and are therefore classified separately Classification should be determined based on anticipated character

Interstates and Other Freeways Interstates –located on the interstate highway system Other freeways-not on the interstate system but are high volume facilities with complete control of access (expressways, multi-lane divided parkways, and parkways with occasional at-grade intersections fall into this category).

Arterials (rural and urban) Carry large traffic volumes between major points

Collector Roads and Streets (rural and urban) Collect and distribute traffic while providing access to abutting properties

Local Roads and Streets (rural and urban) Primary purpose is access to abutting property

Other Roadways Parkways - designated by law Ramps - Turning roadways that connect two or more legs of an interchange Speed Change Lanes - auxiliary lane used for accelerating or decelerating Turning Roadways - separate connecting roadways at high type intersections Collector/Distributor Roads - auxiliary roadways w/in or between interchanges Frontage Roads - auxiliary roadways along controlled access facilities Climbing Lanes - auxiliary lanes provided for ascending steep grades

2.5 Project Data Traffic Terrain Special Routes

Traffic Traffic data ADT (2-way, average daily traffic, time period between 1 day and 1 year) AADT (2-way annual average daily traffic, time period of 1 year) DHV (2-way design hour volume) DDHV (one-way, directional design hour volume) Large Vehicles Trucks, buses, and RV’s (recreational vehicles) Traffic Design Year ETC (Estimated time of completion) ETC + 10 ETC + 20 ETC + 30

Terrain Level Rolling Mountainous

Special Routes Strategic Highway Corridor Network (STRAHNET) - Established by the Department of Defense (min vertical clearance 4.9 m) Designated Qualifying and Access Highways (consists of reasonable access routes for special dimension vehicles) Bicycle Routes National Highway System (NHS)

2.6 Critical Design Elements 1. Design Speed 2. Lane Width 3. Shoulder Width 4. Bridge Roadway Width 5. Grade 6. Horizontal Curvature 7. Superelevation 8. Stopping Sight Distance (Horizontal and Vertical) 9. Horizontal Clearance 10. Vertical Clearance 11. Travel Lane Cross Slope 12. Rollover 13. Structural Capacity 14. Level of Service (applies only to interstate highways) 15. Control of Access 16. Pedestrian Accommodation 17. Median Width

2.6 Critical Design Elements (metric in app) Interstates Other Freeways Rural Arterials Urban Arterials Rural Collectors Urban Collectors Local Rural Roads Local Urban Streets

2.6 Critical Design Elements-other roadways Parkways Ramps Speed Change Lanes Turning Roadways Collector-Distributor Roads Frontage Roads Climbing Lanes

Documenting Design Criteria Exhibit 2-16