Recent Guideline Changes 1 Recent AT Guideline Changes Existing Documents New Technical Documents Bridge Structure Design Criteria Bridge Design Bulletins Bridge Best Practice Guidelines Roadside Design Guide

Recent Guideline Changes 2 Existing Documents Hydrotechnical Design Guidelines Bridge Size Culvert Design Guidelines Culvert Sizing Considerations BPG # 7 – Spread Footing

Recent Guideline Changes 3 New Technical Documents Context of Floods in Alberta Flood Envelope Curve Analysis AT Open Channel Flow Equation Alberta Rainfall Runoff Analysis

Recent Guideline Changes 4 Bridge Structure Design Criteria Section 4e – Bridge Fills –No more CB6-2.3M22 –Headslope tool – elliptical fill transition –Bridge Fill Width = Gross Width + 2m –Fill taper rate – max. 30:1 Section 4b – Min. Bridge Grade –Target minimum = 1% (drainage) –Every effort for 0.5% min. grade

Recent Guideline Changes 5 Bridge Design Bulletins BD # 5 – Retaining Walls near Rivers –Issues : Erosion - outflank/undermine Failure – little warning, catastrophic Repair – extensive, expensive Inspection – specialized, systematic Flexibility – accommodate future stages? –Recommendation : Consider Other Options Design – RPW, piling, structure mod.

Recent Guideline Changes 6 Bridge Best Practice Guidelines BPG # 9 – Rock Protection Typical details Why preferred option Bio – not at bridges

Recent Guideline Changes 7 Roadside Design Guide Bridge Width (Section H5.4.1) : –Min. Bridge Clear Roadway = 9.0m –Match Road Design Clear Roadway –> 9000 AADT, shoulder = 3.0m –Max. shoulder width = 4.0m** –Urban – TAC shy distance (T ) ** Maximum for ring road structures is 3.5 m based on safety audit for AHD SW

Recent Guideline Changes 8 Roadside Design Guide Fig. H7.1 (Underpass Clearance)

Recent Guideline Changes 9 Roadside Design Guide Section H9.2 – Pedestrian/Cyclist –Rural – shoulder OK –Systems Interchange – no pathway/sidewalks –Pathways ( TAC bidirectional multi-use min. ) – 4.2m wide on structure ( 3.0 plus shy dist. ) –WOL + Sidewalk (2.5m wide) typical on low speed/volume arterial bridges *** NOTE: warrants for supplemental urban planned facilities beyond basic in urban areas currently under review

Recent Guideline Changes 10 Future Guidelines/Clarifications Vertical clearances – Pedestrian Structures Parallel versus tapers on urban bridges Use of retaining walls on high speed roadway bridges Maximum/minimum grades/crossfalls on bridges Combined effects of horizontal and vertical geometry on ramp bridges