Traffic Barrier Guidelines Section 3.0 Potential Roadside Obstacles Hands-On Workshop III July

Potential Roadside Obstacles (cont.) Design Options: 1.Remove obstacle 2.Relocate obstacle 3.Reduce impact severity 4.Shield obstacle 5.Delineate obstacle 2

Design Process – Begins at Concept Roadside safety MUST be part of the design process from the start. Examples of common issues:  Embankment Side Slopes  Drainage Structures  Drainage  Gutter  Bridge Design BWA Scope/Work Load Reduced 3

Potential Roadside Obstacles Gutters and Curbs Embankments Sign Supports Bridge Piers, Parapets, Abutments & Bridge Cones Noise Abatement Wall Drainage Structures Ditches Riprap Roadway Lighting ITS Systems Utility Poles Trees Bodies of Water Rock Cuts 4

Type G-3 Gutters 5

Type G-2 Gutters 6

Gutters and Curbs ( Article 3.2) 7 Type “C” Curb Ramp Toll Plaza Only

Gutters and Curbs ( Article 3.2) Gutter may be used with or without guardrail. Guardrail may be used with or without gutter. The need for each is determined independently. Do not use guardrail to shield improperly placed gutter. Guardrail used with gutter shall be at correct offset. 8

Embankments (Article 3.3) Roadside Geometry and Terrain Features, Section of the AASHTO Guide. 9

Embankments (Cont) 10 Recoverable Foreslope – 1:4 (V:H) and flatter Non-Recoverable Foreslope – Between 1:3 (V:H) (inclusive) and 1:4 (V:H) (exclusive) Critical Foreslope – Steeper than 1:3 (V:H)

Vehicle on Critical Foreslope

Comparative Risk Warrants for Embankments (RDG Fig. 5-1b) 12

Preferred Typical Section – Starting Point 13 Barn-roof foreslope using 1:6 allows easier: Placement of signs and light poles Transition to a bridge abutment & bridge cone.

Sign Supports (Article 3.4) Overhead Sign Truss – Cantilever Type Overhead Sign Truss – Span Type 14

Bridge (Article 3.5) Pier Abutment Cone Economical bridge designs usually result in the location of bridge piers, abutments, and parapets within mainline or ramp clear zones. Parapets 15

Noise Abatement Wall (Article 3.6) Non-Crashworthy Noise Wall Crashworthy Noise Wall 16 Not preferred for new installations

NAW Preferred Installations Place Wall Near ROW, Beyond Clear Zone 17

NAW Preferred Installations When along roadway – install crashworthy NAW with snow storage (no guardrail for face of wall) 18

Drainage Structure – Safety End Treatment Direction of Traffic Pipe Runners to match adjacent slope 19

Drainage Structures (Article 3.7) Issues: Headwall not flush with embankment Pipe too short Headwall too close to roadway Steep slope just above headwall Skew 20

Drainage Structures- Corrected 21

Drainage Structure- Issues Issues-Culvert End Treatment Headwall & pipe runners too steep in embankment slope, non traversable Headwall not flush with embankment; obstruction 22

Drainage Structure- Corrected 23

Ditches (Article 3.8) Drainage Channels, Section of the AASHTO Guide. 24

Roadway Lighting (Article 3.10) 25

Standard H1 – Grading Requirements 26

Standard H1 – Grading Requirements 27

Breakaway Light Pole Bases 28

Roadway Lighting (Article 3.10) Controllers and Transformers 29

Communication Systems and ITS Devices (Article 3.11) NID RWIS CCTV Camera Non-Breakaway 30

Bodies of Water (Article 3.14) Bodies of water greater than 2’ in depth must be shielded. Locate detention basins well outside the clear zone. 31

Questions? 32

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