Resolving Conflicts at Complex Intersectionssantafempo.org/wp-content/uploads/2012/06/complex...Skew...

Resolving Conflicts at Complex Intersections

June 20, 2012

APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 1 of 93

Today’s webinar presenters

Michael Moule, PE, PTOE has over 18 years of progressive traffic and transportation engineering experience, including traffic calming, conceptual design for Complete Streets, and theplanning of improved bicycle and pedestrian facilities. His projects accommodate all modes of transportation in order to help cities and states meet their mobility, economic development, safety, and quality of life goals. He has significant innovative design experience and specializes in improving conditions for non-motorized users without degrading motor vehicle capacity. Michael routinely leads community planning processes and training sessions to give citizens the basic skills they need to develop and review street design solutions.


How to claim credit for CM or PDH

To claim credit for Certification Maintenance (AICP) or Professional Development Hours (PDH) for this webinar:

Log your attendance on the CM / PDH sign‐in sheet

Site hosts: return the completed sign‐in sheet to APBP after the webinar (fax to 866‐720‐3611 or e‐mail [email protected])

Attendees: For people who want a Certificate of Attendance: A fillable PDF form may be downloaded and printed here: http://www.apbp.org/?page=Webinar_certificate

Planners: The AICP has approved one CM credit for this webinar. Go to www.planning.org to claim credit.


Resolving Conflicts at Complex IntersectionsAPBP Webinar Series

Michael Moule, PE, PTOE

Principal, Nelson\Nygaard Consulting Associates

June 20, 2012


Geometric ToolsGeometric Tools

5APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 5 of 93

Skewed intersectionsSkewed intersections

Skew increases crossing distance & speed of turning cars6


Philadelphia PA

Cars can turn at high speedCars can turn at high speed7


Skew increases crosswalk length, decreases visibility


Right angle decreases crosswalk length, increases visibility


Problems with skewed intersections10


Minor solutions for skewed intersections

Protected left or right turn phases


Major solution for skewed intersections12


The same principle can be applied to multi-leg intersections13


Large radii:Large radii:1.1. Increase crossing Increase crossing

distancedistance

2.2. Make crosswalk & Make crosswalk & ramp placement ramp placement more difficultmore difficult

3.3. Add uncertainty for Add uncertainty for bicyclistsbicyclists

4.4. Allow fast motor Allow fast motor vehicle turnsvehicle turns

ReduceReducecorner radiicorner radii


Canyonville OR

Minimize curb radiusDonDon’’t choose larger design vehicle than necessaryt choose larger design vehicle than necessary

Bus makes turn several times an hourBus makes turn several times an hour15


Santa Barbara CA

Moving van, once or twice a year; Moving van, once or twice a year; pedspeds cross every daycross every day

Minimize curb radiusMinimize curb radiusDonDon’’t choose larger design vehicle than necessaryt choose larger design vehicle than necessary


Minimize curb radiusMinimize curb radiusLet trucks use 2Let trucks use 2ndnd lanelane


Curb extensionsMost focus is on reduced crossing distance

• Better visibility between peds and motorists• Traffic calming• Room for street furniture

Other advantages:


Better VisibilityBetter Visibility


Crosswalk placement requires balancingCrosswalk placement requires balancingseveral goals that sometimes compete:several goals that sometimes compete:

•• Shortest crosswalk lengthShortest crosswalk length•• Minimal crosswalk setback to:Minimal crosswalk setback to: Reduce outReduce out--ofof--direction traveldirection travel Provide good sight lines between Provide good sight lines between pedspeds and and

motoristsmotorists

•• Proper ramp placement:Proper ramp placement: Ramps entirely contained in crosswalk Ramps entirely contained in crosswalk Two ramps preferred whenever possibleTwo ramps preferred whenever possible


Small corner radii allow two ramps, Small corner radii allow two ramps, shortest crosswalks, direct travel pathsshortest crosswalks, direct travel paths


Larger radii create large undefined areas


Crosswalks at shortest crossing = longer walking distance

Right & leftRight & left--turning drivers donturning drivers don’’t see crosswalkt see crosswalk


Single ramp reduces crosswalk setback but lengthens crosswalk


Balancing the goals works best

Note:Note:Crosswalk length and setback Crosswalk length and setback are greater with large radii than are greater with large radii than with small radiiwith small radii

Note: 3Note: 3”” curb curb exposure between exposure between ramps allows them ramps allows them to be close to be close togethertogether


Corvallis OR

Crosswalk

Crosswalk

Pedestrian crossing

Pedestrian crossing

Crosswalk placement: Observe pedestriansCrosswalk placement: Observe pedestrians


The same principles work at skewed intersections or “ramp-like” connections


Shortest CrosswalkShortest Crosswalk


Most Direct RouteMost Direct Route


Midway Solution Midway Solution –– Balances GoalsBalances Goals


Where to place crosswalk?Where to place crosswalk?

MidwayMidway

Shortest crossingShortest crossing

Mos

t dire

ct ro

ute

Mos

t dire

ct ro

ute

Washington DC

Observe pedestriansObserve pedestrians•• Younger woman takes direct route Younger woman takes direct route (looks over shoulder) (looks over shoulder) •• Older man seeks crosswalkOlder man seeks crosswalk•• Midway would be used by bothMidway would be used by both•• YIELD TO PED signs indicate a problem YIELD TO PED signs indicate a problem


Crosswalk placement: Think like a pedestrianCrosswalk placement: Think like a pedestrianPhiladelphia PA 32


Interchanges Interchanges –– treat each ramp terminus like a treat each ramp terminus like a normal intersection (right angles, bike lane normal intersection (right angles, bike lane

channelization, islands where needed)channelization, islands where needed)33


Single Point Urban InterchangeSingle Point Urban Interchange

Signal timing; 3 movements Signal timing; 3 movements are run through one signalare run through one signal

Takes less ROW than split diamond

1. Through movements2. Left turns in one direction3. Left turns in other direction


How to make SPUI work for pedestrians: Provide continuous sidewalks Break up crossings into several small steps Use good geometry; create tight, right-angle crossings; Make it clear to drivers where to expect pedestrians


How to make SPUI work for cyclists:

Provide continuous bike lanes Use good geometry: tight, right-angle approaches Make it clear to drivers where to expect cyclists Ensure enough green time to cross: advance stop bar

Provide continuous bike lanes Use good geometry: tight, right-angle approaches Make it clear to drivers where to expect cyclists Ensure enough green time to cross: advance stop bar


Aerial view of SPUI that mitigates many of the problems for pedestrians and bicyclists

Salem OR 37APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 37 of 93

Signalization ToolsSignalization Tools


Restricting Turns on RedRestricting Turns on Red

Tampa FL

MUTCD Section 2B.54

Consider No Turn on Red signs where there is:Consider No Turn on Red signs where there is:•• Poor sight distance between vehicles and Poor sight distance between vehicles and pedspeds;;•• An unusual number of An unusual number of pedped conflicts with turns conflicts with turns

on red (compared to on red (compared to turns on green);turns on green);

•• An exclusive An exclusive pedestrian phase; orpedestrian phase; or

•• A leading pedestrian A leading pedestrian intervalinterval


Restricting Turns on Red:Restricting Turns on Red:1.1.At all times At all times

Washington DC 40APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 40 of 93

Restricting Turns on Red:Restricting Turns on Red:2. By time of day 2. By time of day

Limits most turns Limits most turns on redon red

St Paul MN 41APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 41 of 93

Restricting Turns on Red:Restricting Turns on Red:3. Changeable message3. Changeable messagesign sign –– can be activatedcan be activatedwhen when pedped pushes pushes button or as set by button or as set by controllercontroller

Orlando FL

Note: An onNote: An on--demand NTOR sign can be used to demand NTOR sign can be used to improve the effectiveness of a Lead Pedestrian Interval improve the effectiveness of a Lead Pedestrian Interval


Popular because all traffic stops and pedestrians Popular because all traffic stops and pedestrians can cross in any direction can cross in any direction (must ban turns on red)(must ban turns on red)

Exclusive Pedestrian Phase (Barnes Dance)Exclusive Pedestrian Phase (Barnes Dance)

MUTCD Figure 3B-20 (Markings) 43


Pedestrians pay a price in delay:Pedestrians pay a price in delay:Pedestrians wait for traffic in one directionPedestrians wait for traffic in one direction

Pasadena CA 44APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 44 of 93

Pedestrians wait for traffic in other directionPedestrians wait for traffic in other directionPasadena CA 45


Reward: pedestrians can cross in any directionReward: pedestrians can cross in any directionPasadena CA

Exclusive pedestrian phase increases safetyExclusive pedestrian phase increases safety(CMF = 0.66; CRF=34%)(CMF = 0.66; CRF=34%)

but decreases efficiency of intersectionbut decreases efficiency of intersection

Use where there are high Use where there are high pedped volumesvolumesand many turning vehiclesand many turning vehicles


LPI = Lead Pedestrian IntervalLPI = Lead Pedestrian Interval

LPI gives pedestrians a head start

It’s like a “mini” exclusive phase

Link to video of LPI

MUTCD Sec. 4E.06, paragraphs 19-23 47


Looks like a regular signal to drivers: Looks like a regular signal to drivers: greengreen--yellowyellow--redred


LPI : WALK comes on at least 3 seconds prior to the green signal;pedestrians enter crosswalk before turning vehicles arrive there.


Protected Vs. Permissive Left TurnsProtected Vs. Permissive Left Turns


Permissive Left TurnsPermissive Left Turns

Pedestrians cross at same time as left‐turning car;

Drivers turning left on a green ball don’t look for pedestrians.


Pedestrians cross before left‐turning car, with thru‐traffic;

Pedestrian and car not in conflict

Protected Left TurnsProtected Left Turns


Bike SignalsBike SignalsAt unusual At unusual intersections, bikeintersections, bike--specific signals can be specific signals can be used to provide a used to provide a specific phase to specific phase to bicyclists bicyclists

Davis CA

Note: Bike signals are still under experimental use Note: Bike signals are still under experimental use (except in California)(except in California)


ExamplesExamples


Bend, OregonBend, Oregon

Revised SkewRevised Skew


Bend ORBend OR

Skewed intersection reduces visibilitySkewed intersection reduces visibilityDriver looks left, doesnDriver looks left, doesn’’t see pedestrian on rightt see pedestrian on right


Adjust skew by bringing out curbAdjust skew by bringing out curb

Bend OR 63APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 63 of 93

Result: driver behavior changeResult: driver behavior change

Bend OR 64APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 64 of 93

Salem, OregonSalem, Oregon

Curb Extension and Reduced Curb Extension and Reduced Corner RadiusCorner Radius


Before: high speed rightBefore: high speed right--turnsturns


After: slow speed rightAfter: slow speed right--turnsturns

Curb extension and new corner radius must be Curb extension and new corner radius must be designed together designed together –– see earlier radius discussionsee earlier radius discussion


Before: Pedestrians wait where they can see, in the streetBefore: Pedestrians wait where they can see, in the street

After: curb ext. puts him where he can see and be seenAfter: curb ext. puts him where he can see and be seenSalem OR 68


Asheville, NCAsheville, NC

Reconfigured intersection at Reconfigured intersection at downtown squaredowntown square


Before: Huge intersection; exclusive ped phaseBefore: Huge intersection; exclusive ped phase70Asheville NC


After: smaller intersection, better crosswalksAfter: smaller intersection, better crosswalksAsheville NC 71


Springfield, OregonSpringfield, Oregon

Reconfigured interchange rampReconfigured interchange ramp


Flat angle = wide crossing & highFlat angle = wide crossing & high--speed turnsspeed turnsTight angle = short crossing & slow speed turnsTight angle = short crossing & slow speed turns

Springfield ORSpringfield OR

Old ramp alignmentOld ramp alignment

Reconfigured Ramp TerminusReconfigured Ramp Terminus


•• Red line = old crosswalkRed line = old crosswalk•• Green line = new crosswalkGreen line = new crosswalk

Springfield OR

Reconfigured Ramp TerminusReconfigured Ramp Terminus


BeforeBefore

75Springfield ORAPBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 75 of 93

AfterAfter

Springfield OR 76APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 76 of 93

San Francisco, CASan Francisco, CA

Removal of 5Removal of 5thth leg of intersection leg of intersection (the inexpensive way)(the inexpensive way)

Market Street / Castro Street / 17Market Street / Castro Street / 17thth StreetStreet


BeforeBefore78San Francisco

CA APBP Webinar Series Resolving Conflicts at Complex Intersections | 6-20-2012 78 of 93

AfterAfter79San Francisco


BeforeBefore80San Francisco


AfterAfterSan Francisco CA


Portland, OregonPortland, Oregon

Bike signal for path at Bike signal for path at intersection cornerintersection corner


BeforeBefore84Portland OR


AfterAfter85Portland OR


AfterAfterPortland OR 86


New York CityNew York City

All of the aboveAll of the above

Not Times SquareNot Times Square

St. Nicolas Ave at Amsterdam AveSt. Nicolas Ave at Amsterdam Ave


BeforeBefore88New York City


AfterAfter89New York City


BeforeBeforeNew York City 90


AfterAfter91New York City


92

Michael Moule, PE, TE, PTOE116 New Montgomery Street

San Francisco, CA 94105(415) 284-1544

[email protected]


Thank you to our generous webinar sponsors


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