1. Design Criteria
CTC 440

2. Objectives Know what “design criteria” means
Determine design criteria for various types of facilities
Reference:

3. 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

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

5. 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.

6. 2.3 Design Criteria Sources
A Policy on Geometric Design of Highways and Streets (2011)
A Policy on Design Standards, Interstate System (2016)
NYSDOT Bridge Manual
Guidelines for Highways within the Adirondack Park
Proposed Guidelines for Pedestrian Facilities in Public Right-of-Way
Urban Street Design Guide
NCHRP (National Cooperative Highway Research Program

7. 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

8. 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).

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

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

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

12. 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

13. 2.5 Project Data
Traffic
Terrain
Special Routes

14. 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

15. Terrain
Level
Rolling
Mountainous

16. 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)

17. National Highway System (NHS)
Approved in Separate from functional classification.
All interstates are part of NHS

18. 2.6 Critical Design Elements
1. Design Speed
2. Lane Width 
3. Shoulder Width
4. Horizontal Curve Radius
5. Superelevation
6. Stopping Sight Distance (Horizontal and Vertical)
7. Maximum Grade
8. Cross Slope
9. Vertical Clearance
10. Design Loading Structural Capacity
11. ADA Compliance

19. Design Load Structural Capacity

20. Documenting Design Criteria Exhibit 2-16