# Chap 4 Cross Section Elements (pp.4-1 – 4-66 ) The following topics (pages) are covered in this lecture: Pavement (p.4-1 – 4-7) Pavement (p.4-1 – 4-7)

## Presentation on theme: "Chap 4 Cross Section Elements (pp.4-1 – 4-66 ) The following topics (pages) are covered in this lecture: Pavement (p.4-1 – 4-7) Pavement (p.4-1 – 4-7)"— Presentation transcript:

Chap 4 Cross Section Elements (pp.4-1 – 4-66 ) The following topics (pages) are covered in this lecture: Pavement (p.4-1 – 4-7) Pavement (p.4-1 – 4-7) Lane width (p.4-7 – 4-8) Lane width (p.4-7 – 4-8) Shoulders (p.4-8 – 4-14) Shoulders (p.4-8 – 4-14) Drainage Channels (p.4-20 – 4-27) Drainage Channels (p.4-20 – 4-27) Pedestrian Facilities (p.4-56 – 4-66) Pedestrian Facilities (p.4-56 – 4-66) 1

4.2 Cross Section 2 www.Visual Dictionary On-line.com

Roadway vs. Traveled Way Roadway: The portion of a highway, including shoulders, for vehicular use. A divided highway has two or more roadways. Traveled Way: The portion of the roadway for the movement of vehicles, exclusive of shoulders. 3

Roadway Assembly in Civil 3D 4

Typical Cross Section Normal Crown High-type surface: 1.5 to 2.0% Low-type surface: 2 to 6% 6 Fig. 4-1

Typical Cross Section Superelevated 7 Fig. 4-2

Roadway Sections for Divided Highway 8 Fig. 4-3

4.3 Lane Width 9 to12 ft, 12 ft predominant 9 to12 ft, 12 ft predominant 11 ft acceptable 11 ft acceptable 9 ft acceptable for low-volume roads in rural & suburban areas 9 ft acceptable for low-volume roads in rural & suburban areas Narrow inside lanes may be OK, like 10 to 11 ft inside lanes and 12 to 13 ft outside lanes to accommodate bikes Narrow inside lanes may be OK, like 10 to 11 ft inside lanes and 12 to 13 ft outside lanes to accommodate bikes Auxiliary lanes (like left turn lanes) can be 10 ft, but TWLTL should have 10- to 16-ft Auxiliary lanes (like left turn lanes) can be 10 ft, but TWLTL should have 10- to 16-ft 9 These values remain the same in HCM 2010.

4.4 Shoulders 10 Fig. 4-4

Importance of Shoulders Space for vehicles with problems to park Space for vehicles with problems to park Space for drivers to stop and check maps, etc Space for drivers to stop and check maps, etc Space for evasive maneuvers to avoid collisions Space for evasive maneuvers to avoid collisions The sense of openness The sense of openness Help providing required sight distance Help providing required sight distance Increased aesthetics Increased aesthetics Improved capacity Improved capacity Space for maintenance operations (snow & storage) Space for maintenance operations (snow & storage) Lateral clearance for signs and guardrails Lateral clearance for signs and guardrails Discharge storm water away from the edge of pavement (reduce pavement breakup) Discharge storm water away from the edge of pavement (reduce pavement breakup) Structural support for the pavement Structural support for the pavement Space for pedestrians and bicycles Space for pedestrians and bicycles 11

4.4.2 Shoulder Width Desirably, a vehicle stopped on the shoulder should clear the edge of the traveled way by at least 1 ft, and preferably 2 ft.  10 ft min width (Semi-trailer width is about 8 ft.) Desirably, a vehicle stopped on the shoulder should clear the edge of the traveled way by at least 1 ft, and preferably 2 ft.  10 ft min width (Semi-trailer width is about 8 ft.) A minimum of 2 ft for the lowest-type highway, and 6 to 8 ft preferred A minimum of 2 ft for the lowest-type highway, and 6 to 8 ft preferred A minimum of 10 ft, preferably 12 ft for high- type high-volume roads A minimum of 10 ft, preferably 12 ft for high- type high-volume roads A min clearance of 4 ft to barriers A min clearance of 4 ft to barriers A shoulder should be continuous A shoulder should be continuous 12

4.4.3 Shoulder Cross Section Depends on the type of shoulder construction Depends on the type of shoulder construction Bitumen/concrete-surfaced: 2 to 6% Bitumen/concrete-surfaced: 2 to 6% Gravel/crushed-rock: 4 to 6% Gravel/crushed-rock: 4 to 6% Turf: 6 to 8% Turf: 6 to 8% The max algebraic difference in the traveled way and shoulder grades should be from The max algebraic difference in the traveled way and shoulder grades should be from 6 to 7% (be careful especially at the higher side of the segments with superelevation (i.e., grade break) And, which values should be used at the Moark Junction? 13

4.4.4 Shoulder Stability Paved or stabilized shoulders offer numerous advantages Paved or stabilized shoulders offer numerous advantages 1) Provision of refuge for vehicles during emergency 2) Elimination of rutting and drop-off adjacent to the edge of the traveled way 3) Provision of adequate cross slope for drainage of roadway 4) Reduction of maintenance, and 5) Provision of lateral support for roadway base and surface course 14

4.8 Drainage Channels and Sideslopes Drainage channels should have adequate capacity for the design runoff, provide for unusual storm water with minimum damage to the highway, and be located and shaped to provide a safe transition from the roadway to the back slope. Drainage channels should have adequate capacity for the design runoff, provide for unusual storm water with minimum damage to the highway, and be located and shaped to provide a safe transition from the roadway to the back slope. Drainage channels include (1) roadside channels in cut sections, (2) toe-of- slope channels to convey the water from any cut section to the natural watercourse, (3) intercepting channels placed back of the top of cut slopes to intercept surface water, and (4) flumes to carry collected water down steep cut or fill slopes. Drainage channels include (1) roadside channels in cut sections, (2) toe-of- slope channels to convey the water from any cut section to the natural watercourse, (3) intercepting channels placed back of the top of cut slopes to intercept surface water, and (4) flumes to carry collected water down steep cut or fill slopes. (2) Foreslope: 1V:4H or flatter recommended (5) Backslope: 1V:3H or flatter recommended (if steeper than 1V:2H, consider retaining walls) 15 Fig. 4-6

4.17.1 Sidewalks 8 ft considered an appropriate minimum. 8 ft considered an appropriate minimum. In residential areas, 4 to 8 ft. In residential areas, 4 to 8 ft. A planted strip between the traveled-way curb and sidewalk should be min 2 ft wide for maintenance purpose. A planted strip between the traveled-way curb and sidewalk should be min 2 ft wide for maintenance purpose. Where sidewalks are placed adjacent to the curb, make it 2 ft wider than the minimum required when they are placed with a planted strip. Where sidewalks are placed adjacent to the curb, make it 2 ft wider than the minimum required when they are placed with a planted strip. In general, wherever roadside and land development conditions affect regular pedestrian movement along a highway, a sidewalk or path area, as suitable to the conditions, should be furnished. In general, wherever roadside and land development conditions affect regular pedestrian movement along a highway, a sidewalk or path area, as suitable to the conditions, should be furnished. As a general practice, sidewalks should be constructed along any street or highway not provided with shoulders, even though pedestrian traffic may be light. As a general practice, sidewalks should be constructed along any street or highway not provided with shoulders, even though pedestrian traffic may be light. Sidewalks should have all-weather surface to ensure their intended use. Sidewalks should have all-weather surface to ensure their intended use. 16

US 89 Cross Section 17

Google Earth: Street View 18 South of Moark Junction US6, Looking west North of Moark Junction US89, Looking north North of Moark Junction US6, Looking east North of Moark Junction, near 2 nd South US89, Looking north

4.17 Pedestrian Facilities 19

Complete Street Design http://www.completestreets.org/complete-streets-fundamentals/ Complete Streets are streets for everyone. They are designed and operated to enable safe access for all users. Pedestrians, bicyclists, motorists, and public transportation users of all ages and abilities are able to safely move along and across a complete street. Complete Streets make it easy to cross the street, walk to shops, and bicycle to work. They allow buses to run on time and make it safe for people to walk to and from train stations. 20

Urban Milwaukee Makeover (South 2 nd Street) 21

Daybreak, Utah 22

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