RoundaboutsRoundabouts LessonsLessonsRoundabouts Roundabouts –– Lessons Lessons Learned During the Public Learned During the Public Support Design andSupport Design andSupport, Design and Support, Design and Construction PhasesConstruction PhasesPublic Works Congress and ExpositionPublic Works Congress and Exposition

August 19, 2008August 19, 2008gg

IntroductionsIntroductionsIntroductionsIntroductions

Larry Murphy, P.E.CDM Deputy Director of Transportation24 years experienceFormer ConnDOT Highway Engineer

Kevin Johnson, P.E.Principal with CDMPrincipal with CDM15 years experienceSenior Transportation EngineerSenior Transportation Engineer

ObjectivesObjectives

How to build public support for roundaboutsLessons learned during the design phase of a roundabout projectLessons learned during the construction andLessons learned during the construction and maintenance phase of a roundabout project

Public SupportPublic Support

Roundabouts are not your father’s intersection designKeep the community informed early on in the design processProper notification of key stakeholders (bikeProper notification of key stakeholders (bike groups, wetlands agency)Avoid moving forward on a project without p blic s pportpublic support

Public Support Public Support (Cont.)(Cont.)

Building a project without public support could create bad press and an angry mob.

Public Support Public Support (Cont.)(Cont.)

What a roundabout isn’t!

Public Support Public Support (Cont.)(Cont.)

How do you build public support for an unfamiliar intersection improvement?

Public Support Public Support (Cont.)(Cont.)

One successful technique is a design charrette!

Public Support Public Support (Cont.)(Cont.)

A What…?

Charrette

A charrette (pronounced [shuh-ret], often misspelled charette and sometimes called a design charrette) g )consists of an intense period of design activity.

Wikipedia

History of CharrettesyParis – 19th CenturyThought to originate from the École desThought to originate from the École des Beaux-Arts in Paris in the 19th Century, the word charrette is from the French for "cart" or "chariot".

Student architects still working furiously on the grand illustrations that were their design presentations literallywere their design presentations, literally in the cart ("en charrette"), as they were wheeled through the streets of Paris on their way at the very last minute to turn i th i k t th i fin their work to their professors.

Wikipedia

Public Support Public Support (Cont.)(Cont.)

Public Support Public Support (Cont.)(Cont.)

Why Have a Charrette?

Old DOT Design ProcessNIMBYsNIMBYsIncorporates Context Sensitive Solutions into th D ithe Design

Public Support Public Support (Cont.)(Cont.)

Charrette Example – Rt. 116, Amherst, MA

Public Support Public Support (Cont.)(Cont.)

Break Into Groups

Public Support Public Support (Cont.)(Cont.)

Group Design Concept

Public Support Public Support (Cont.)(Cont.)

Try to Achieve Consensus

Public Support Public Support (Cont.)(Cont.)

Day 2 – Formulized Concept

Public Support Public Support (Cont.)(Cont.)

The end result of the Charrette was a concept supported by the community and DOT.

Public Support Public Support (Cont.)(Cont.)

Successful Design Public Hearing

Public Support Public Support (Cont.)(Cont.)

Although There are No Guarantees

Historically the term charretteis also applied to the cart used to carry the condemned to the guillotine!

Lessons Learned in the Design Phase Lessons Learned in the Design Phase ggof a Roundabout Projectof a Roundabout Project

You’ve survived the public hearing process, now it’s time to work on the design of a

d b t!roundabout!Objective of this presentation is to offer some key considerations for a roundabout.yThis presentation will not teach you how to design a roundabout.

Design Phase Design Phase (Cont.)(Cont.)

Key ConsiderationsPublic supportSafetyFeasibilityGeometryTraffic and special eventsPedestrians and bicyclesPedestrians and bicyclesLightingLandscapingLandscapingTraffic calming

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Public SupportPublic awareness and communication does not stop when the charrette is completed!Maintain contact with key stakeholdersR b th b i t th !Remember, the mob is out there!

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

SafetyIn general, roundabouts have been proven to be safer than traffic signal locations.

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

FeasibilityHow much money is a roundabout compared to a traffic signal installation?

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

FeasibilityConsiderations

– Installation – site dependent– ROW – roundabouts require wider nodes, traffic

signal require wider approach lanessignal require wider approach lanes– Operation and Maintenance – Traffic signals

cost approximately $15,000/year however; roundabout need lighting and landscapingroundabout need lighting and landscaping

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

GeometrySevere side slopes may prohibit roundaboutsBe aware of encroachment into wetlandsROWSignificant changes in horizontal or vertical grades will impact the design of roundaboutDiameter of a the roundabout may not fit yourDiameter of a the roundabout may not fit your location. Diameter is determined by the number of lanes, geometry, trucks and traffic demanddemand.

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Geometry Example – Missoula, Montana

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Truck Aprons

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Truck Aprons

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Traffic and Special EventsNo your limits for a roundabout!!

– Roundabouts have a breaking point for circulating and entry volumesEntering volume and distribution (left turners)– Entering volume and distribution (left turners) are key

– Truck traffic must be known and included in the designdesign

– Talk to your emergency response officials– Be careful of special eventsp

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Special Events – Missoula,

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Traffic simulation

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Pedestrian and BicyclistsAre roundabout safe for peds and bikes?What design considerations are there?

– Splitter islands– Shared bike/ped path– Proper markings and signage

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Pedestrian and BicyclistsSplitter Islands – Yes!

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Pedestrian and BicyclistsShared bike/ped path

– Why?

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Pedestrian and bicycle markings and signs

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

LightingProper lighting of a roundabout is a must.Lighting techniques need to be considerate of the location.Li hti l i i d dLighting analysis is recommended

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Lighting

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

LandscapingNo fountains, playgrounds, obstructions

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Traffic CalmingRoundabouts are an effective method to slow traffic however, the entering volume needs to slow down BEFORE the roundabout.Methods to slow entering vehiclesMethods to slow entering vehicles

– Signing and markings– Rumble strips– Physical alterations to approach

Design PhaseDesign PhaseDesign Phase Design Phase (Cont(Cont.).)

Traffic Calming Methods

Lessons Learned in the Construction Lessons Learned in the Construction Maintenance Phase of a RoundaboutMaintenance Phase of a RoundaboutMaintenance Phase of a Roundabout Maintenance Phase of a Roundabout ProjectProject

Once the design documents are complete the project is ready to be constructed.This part of the presentation will offer some “lessons learned” on constructing and maintaining a roundabout.g

C t ti d M i t PhC t ti d M i t PhConstruction and Maintenance PhaseConstruction and Maintenance Phase(Cont.)(Cont.)

Key ConsiderationsPublic AwarenessPartnership with contractorNotify utility companiesTraffic managementMaintenance

Construction and Maintenance PhaseConstruction and Maintenance PhaseConstruction and Maintenance Phase Construction and Maintenance Phase (Cont.)(Cont.)

Public Awareness – Keep the public informed of the construction progress

Website updatesMonthly or “As-Needed” meetings with the abutters and officialsabutters and officialsNewspaper notificationsDetour planDoor to door visits

Construction and Maintenance PhaseConstruction and Maintenance PhaseConstruction and Maintenance Phase Construction and Maintenance Phase (Cont(Cont.).)

Partnership with ContractorThis may be the contractor’s first roundaboutDetailed plans and specifications are a mustThe more information the better.

Construction and Maintenance PhaseConstruction and Maintenance PhaseConstruction and Maintenance Phase Construction and Maintenance Phase (Cont(Cont.).)

Notify utility companiesRoundabouts impact a wide area and will probably involve the relocation of above and below ground utilities.

Construction and Maintenance PhaseConstruction and Maintenance PhaseConstruction and Maintenance Phase Construction and Maintenance Phase (Cont(Cont.).)

Traffic ManagementPropose a traffic management plan that allows the contractor to work quickly with limited impacts to abutters.

Construction and Maintenance PhaseConstruction and Maintenance PhaseConstruction and Maintenance Phase Construction and Maintenance Phase (Cont(Cont.).)

Roundabout Maintenanceprune and weed the islands and circle (build civic pride)Consider a water tap in the center island for watering plants and flowerswatering plants and flowersNorthern states – snow removalInspect truck apron

ClosingClosingClosingClosing

Generate public support throughout the life of the projectUse common sense when proposing a roundabout. There are several design considerations that must be reviewed.Constructing a roundabout requires detailed plans and a partnership with the contractor.

Reference MaterialReference MaterialReference MaterialReference Material

FHWA – “Roundabouts: An Informational Guide”AASHTO – “Guide for the Development of Bicycle Facilities”National Charrette Institute – “The CharretteNational Charrette Institute The Charrette Handbook”

Questions?Questions?Questions?Questions?