Council Minutes - Town of Cambridge

COUNCIL MINUTESTUESDAY 26 JUNE 2012right turn queue in the AM peak potentially extending back into the Grantham Streetroundabout.• SIDRA modelling of operation of The Boulevard eastbound right turn lane suggests thatthe length of lane is currently insufficient and removal of the filter will introduce the needfor increase to the lane length. Further SIDRA evaluation of operation of this intersectionsuggests that other improvement measures should also be introduced to maintainintersection efficiency. A total of 5 options were considered and evaluated.The result of this evaluation recommends that the following intersection modifications beintroduced:-• Remove the right turn filter for The Boulevard eastbound to Howtree Place southbound;• Extend the eastbound right turn lane on The Boulevard from 70 metres to 160 metres;• Add a left turn pocket on The Boulevard westbound to Howtree Place southbound; and• Mark painted pedestrian crossings on both "give way" left turn slip lanes.The second recommendation was considered for the following reasons:-Add Left Turn Pocket on The Boulevard WestboundWestbound traffic on The Boulevard turning left into Howtree Place has a Left Turn Slip underGive Way control. Entry to the slip is blocked at any time by a queue of two or more vehicles inthe abutting through lane. Use of the slip lane is therefore normally restricted to times wheneastbound traffic on The Boulevard is moving and as a consequence left turning traffic is heldup in the through lane adding to the length of through lane queue.Extension of the current slip lane to The Boulevard eastbound bus bay will increase efficiencyof operation.Pedestrians crossing The Boulevard from south to north on the east side of Howtree Placehave restricted sightlines of oncoming left turning traffic. There is a short time of entry into theslip lane for vehicles turning from the abutting through lane. This can be difficult for pedestriansto judge when motorists fail to provide sufficient signal intent for the turn. Lengthening the sliplane to crease a left turn pocket allows for vehicles to enter the turn lane further from theintersection and provides pedestrians with more time to view oncoming vehicles making the leftturn.Creation of the left turn pocket does not require modification to the traffic signals and willimprove intersection operational efficiency and safety. This improvement is recommended andcan be undertaken standalone.A concept sketch for widening of The Boulevard to achieve extension of the right turn pocketand introduction of a left turn pocket is included as an attachment to this report.As these proposals involve modifications to traffic control signals, Main Roads WA "in principle"endorsement is required prior to the submissions of black spot funding application.It is recommended that these preliminary proposals be endorsed by Council to allow for arequest to be made to Main Roads WA for "in principle" agreement, detailed drawings andestimates prepared and submission to be prepared for black spot funding in the 2013/2014allocation.H:\CEO\GOV\COUNCIL MINUTES\12 MINUTES\JUNE 2012\C CR.DOCX 67