Agenda - Parks and Recreation Commission - 01/12/1995

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Feb. 8, 1983 H. CLEAR ZONE (distance from bikeway to traveled way) For on-road bikeways refer to the bikeway design tables to assess the road suitab/lity for b/cycle travel. The tables wiZl also enable "pretesting" of shoulder widen- inq and ~rfacinq. Bike traffic must flow the .tame direction as adjacent motor vehicle traffic. Two.way bike traffic on one-side of the road is not permitted. For off-road bikeways, there are two categories: roads without curbs and roads with curbs. The proper set back from the traveled way is an important consideration for the designer because operation of the facil/ty is de- pendent upon adequate separation from each respective travel mode (motor vehicle, bike, pedestrian) and ssa- tionary objects (poles, signs...). See Figure G. I. DRAINAGE For bfke routes and lanes the exist/rig roadway drain- a~e is normally adequate. However, on curb and gutter sections a check of ponding depths should be made and corrective action proposed if depths are significant. This may entail improved grate designs or wider bike lanes. On off-road h/keways, the surface of the bikeway should have a cross-slope of two percent for the proper dra/nage. Sloping in one direction usually m'npiifies long5 tudinai drainage design and surface construction, and accordingly, is the preferred practice. Ordinarily, surface drainage from the path will be adequately dissipated as it flows down gently sloping terrain. However, when the bikeway is constructed on the side of a hill, a drainage ditch of suitable dimensions may be necessary on the uphill side to intercept the hillside drainage. See Figure H. Cul- verts or bridges are neces~a-y where a bikeway crosses a drainage channel. Sizing of the required waterway opening should be determined by a hydraulics enczineer. MinLmum culvert size used for bikeway drainage should be 18 inch diameter. Drainage inlet grates on bikeways shall have openings narrow enough and short enough to assure b/cycle fires will not drop into the grates regardless of the direction of b/cycle travel. Where it is not immediately feasible to re- place existing grates with standard grates designed for b/cycles, 1 inch x 1/4 inch steel cross straps should be welded to the grates at a spacing of 6 inches to 8 inches on center, to reduce the size of the openings. See Standard Plates 4151 and 4152 for acceptable designs of grates. BIKEWAYS I II II (ROADS WITHOUT CURBS) L e' J. ~o' M,N. .I. TRAVE~EO ~ T ""'"" PAVED BIKEWAY (ROADS WITH CURBS)' . / / t MIN. PAVED BIKEWAY I I I i I I 'P'ROVIDES ROOM FOR SIGNS, POLES,'E~rC. FIGURE G 2% Bikeway I I I FIGURE H