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• 1. On road The structural section of an off-road bikeway should be desgned in the same manner as a highway, with con- Bicycle travel shall be in the same direction as sideration given to the quality of the subsoil and the • adjacent motor vehicle traffic in compliance with the antiapated loads the bikeway will experience. P;inc;.al uniform vehicle code. A mind num width and lateral loads 'viii normally be from maintenance and emergency clearance will depend on the location of the lane within the vehicles. These vehicles should be restricted to less than 4 roadway and parking conditions.The bikeway design tables or 5 ton axle loads, especially in the spring. provide widths for various roadway conditions. The gutter section of a curb and gutter should normally not be con- Bituminous surfacing is recommended. Figure F sdered as a part of the bicycle lane since the joint between provides typical surfacing designs for full depth bitumin- the gutter and roadway surface can be very hazardous to a ous and aggregate base sec:ons. cyclist. • 2. Off-road Bikeways —a___ FULL DEPTH The con section of an off-road bikewaycan be 2" to 6" 1 determined from the widths and clearances presented. T -C•� ��c `• t The minimum widths based on the number of lanes are -:e. '-=c;1/4_,-.`z.•,_2 ••"`�: �- as follows: bl• 4 n Number of Minimum Paved Width AGGREGATE BASE Lanes feet 1 4.0 1 1/2" 3 .................... 2 8.0 „ 3 to 7 • `4 • In addition, a minimum two foot graded area on each side of the bikeway should be provided adjacent to the paved surface. See Figure E on page 27. It should be emphasized ▪ f; y��-" that the minimum width and clearances are for bicycle needs and are not r.:f5cient to accommodate maintenance 1. Spec. 2331 Weaiu:g Course (Full Depth) and emergency vehicles (pickups, mowers, ambulances, 2. Compacted Subcrade etc.). Accordingly, the minimums may have to be adjusted, as necessary, to provide for these considerations. In ad- 3. Spic. 2331 Wearing Course dition to the widths provided above, additional widths 4. Class 5 Aggregate Base should be provided for sharp curves and where steeper 5. Compacted Subyrade grades are necessary. On steep grades, additional width is necessary due to increased speed and needed room for maneuverability. On sharp coves,less than 100 foot radius, FIGURE F additional width may be needed due to bicycle lean. The TYPICAL OFF-ROAD DESIGN SECTIONS following values are recommended for widening: Radius Additional Paved Width – The lighter sections should be used only in granular feet feet rsbsoiis. -25 25 50 4 – Topsoils and other organic soils should be removed. 3 50-75 7S N 5 i – A 1 foot subcut should be provided for uniformity 100+ 0 and compaction. G. STRUCTURAL SECTION – Granular subgrades may require a minimum1 Lich Grass 1 stabilizing aggregate, especially in the full depth bituminous section. For bike routes and lanes the inplace surfaced strut- – Consideration should be given to increasing the asphalt rare is normally adequate. When a roadway with unpaved shoulder is to be surfaced for a bike lane, standard Mn/DOT• ��"tent by 1 to 2% to provide increased pavement life. shoulder designs should be specfted. Subgrade and surfacing recommendation should be requested from a Materials or Soils Engineer. 127