RES 95024X - Laserfiche WebLink

Technical Procedures STEP 3: Phasing I~ Identify the type of phasing (,protected lefts turns, shared, or split) to be used at the intersection. --- STEP 4: Left-Tun Check The left turn check will apply to Level of Service calculations for future " conditions where the demand is estimated. Determination of the need for left turn phasing for existing conditions should be made based on actual traffic count, left turn delay, observed queuing and accident history data. If permissive !eft turn phasing is provided, a check must be made to determine if sufficient left turn capacity if provided. The left turn capacity is the combination of left turn made against opposing through movements and left made during the _ yellow change interval. II The capacity during the yellow change interval (Vc) -- the maximum numbers ._ of left turns that can clean in this period -- equals two times the number of signal cycles per hour. If the number of cycles per hour is not known, assume that the maximum number of left turns that can clear the intersection in one hour equals 90. - II The capacity for left turns during the green cycle (Vt.) -- the maximum number of left turns that can clear against opposing traffic volumes -- is estimated using the following equation: Where: Vt. = left-tun volume, in vehicles per hour, that can clear during the green for opposing through traffic. G = maximum green plus yellow time. * C = cycle time for opposing through traffic.* Vo = sum of opposing through and right-turn volumes, in vehicles per hour.