Laserfiche WebLink
APPENDIX B <br /> SUMMARY OF LEVELS OF SERVICE FOR INTERSECTIONS <br /> FROM THE HIGHWAY CAPACITY MANUAL, 1965 <br /> Level of Type of Flow Delay Maneuverability <br /> Service <br /> A Free flow No vehicle waits longer Turning movements are easily <br /> than one red indication. made, and nearly all drivers -1 <br /> find freedom of operation. <br /> B Stable flow The number of vehicles Many drivers begin to feel <br /> waiting through one red somewhat restricted within <br /> indication is increased . groups of vehicles . <br /> C Stable flow Occasionally vehicles Back--ups develop behind <br /> (Design may have to wait through turning vehicles. Most drivers <br /> Level) more than one red indi- feel somewhat restricted, but <br /> cation. not objectionably so. <br /> D Approaching Delays may be substan- Maneuverability is severely <br /> unstable flow tial during short limited during short periods <br /> periods, but excessive due to temporary back-ups. <br /> back-ups do not occur . <br /> E Unstable flow Delay may be great--up There are typically long queues <br /> (Capacity) to several signal of vehicles waiting upstream of <br /> cycles. the intersection. <br /> F Forced flow Excessive delay. Jammed conditions. Back-ups <br /> from other locations may <br /> restrict or prevent movement <br /> of vehicles at the intersection <br /> under consideration. <br />