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Rotaries to Roundabouts in Massachusetts. Andy Paul MassDOT HQ – Traffic Operations Joe Frawley MassDOT District 3 – Traffic Engineer. Existing Rotaries. More than 100 existing rotaries. WEYMOUTH – ROUTE 3 / UNION STREET. HUDSON – ROUTE 62 / ROUTE 85. Existing Rotaries.
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Rotaries to Roundaboutsin Massachusetts Andy Paul MassDOT HQ – Traffic Operations Joe Frawley MassDOT District 3 – Traffic Engineer
Existing Rotaries More than 100 existing rotaries WEYMOUTH – ROUTE 3 / UNION STREET HUDSON – ROUTE 62 / ROUTE 85
Existing Rotaries BOSTON – COLUMBIA ROAD / MORRISSEY BLVD. / WILLAM J. DAY BLVD. EVERETT – ROUTE 99 (BROADWAY) / MAIN STREET
Problems with Rotaries • Geometric deficiencies • Wide circulatory roadway • Large circle radius • Entry angle • Crashes resulting from deficiencies • Rear-end • Sideswipe, same direction • High rate of injury crashes • Negative public perception
Example Rotary • Worcester – Newton Square WIDE CIRCULATORY ROADWAY HIGH APPROACH SPEEDS CAUSED BY LACK OF DEFLECTION NO LANE-USE MARKINGS ON MULTI-LANE APPROACHES
How to Improve a Rotary • Low Cost, Short Term • Upgrading Signs and Pavement Markings • Moderate Cost, Medium Term • Modify Approach Geometry (examples: splitter island, entry width, exit radius) • Higher Cost, Long Term • Reconstruct as a Roundabout
Low Cost • Revere – Brown Circle • Population: 51,693 • Average of 48 Crashes per Year • 3 Truck Rollovers in 3 Years • Entering ADT = 75,000 Crash Rate
Revere Existing Aerial
Revere Existing Aerial NO LANE-USE MARKINGS ON MULTI-LANE APPROACHES WIDE CIRCULATORY ROADWAY NO SPLITTER ISLAND ON APPROACH
Revere • Proposed upgrade of signs and markings
Low Cost • Gardner – Route 2 / Route 68 Interchange • Population: 20,972 • Entering ADT = 25,000 (2005)
Gardner • Birds-Eye View
Gardner Birds-Eye View LARGE CIRCLE RADIUS WIDE CIRCULATORY ROADWAY POOR ENTRY ANGLE
Gardner • Proposed upgrade of signs and markings
Moderate Cost • Greenfield – Interstate 91 / Route 2 / Route 2A Interchange • Population: 17,537 • 39 Crashes from 2005 – 2007 • Entering ADT = 36,000 (2004) • 80% Rear-End Crashes • 44% Injury Crashes Crash Rate
Greenfield • Birds-Eye View
Greenfield • Before LARGE CIRCLE RADIUS WIDE CIRCULATORY ROADWAY POOR ENTRY ANGLE
Greenfield • Concept Plan
Greenfield • Modified approach geometry
Greenfield • Upgraded signs and pavement markings
Moderate Cost • Greenfield – Interstate 91 / Route 2 / Route 2A Interchange • Project Constructed in 2008 • Project Cost: $1.0 million • Governor’s Highway Safety Funds were used for construction
Moderate Cost • Holyoke – Route 202 / Lyman Street • Population: 40,005 • Existing ADT = 10,000 • 75% Rear-End • 25% Injury Crashes Crash Rate
Holyoke • Birds-Eye View
Holyoke • Existing / Proposed
Higher Cost • Worcester – Washington Square • Population: 182,421 • 66 Crashes from 2002 – 2006 • Entering ADT: 36,250 (2000) • 59% Rear-End Crashes • 27% Injury Crashes Crash Rate
Worcester Birds-Eye View
Worcester Birds-Eye View PEDESTRIAN CROSSING TO CENTRAL ISLAND POOR ENTRY ANGLE LARGE CIRCLE RADIUS (R = 300’) NO LANE-USE MARKINGS ON MULTI-LANE APPROACHES
Worcester Reconstructed as a roundabout
Worcester Beginning of Construction
Picture of Completed RDB Worcester After Construction
Higher Cost • Worcester – Washington Square • First multi-lane roundabout in MA • Construction Completed in 2008 • Project Cost: $8.8 million • Included utility relocation and three signalized intersections
How to Improve a Rotary Full reconstruction is not needed for every rotary Examine crash data to determine cause Determine geometric deficiencies In many locations, making improvements to the rotary approaches can significantly improve safety
Thank You • Any Questions? • Contact Information • Andy Paul • MassDOT HQ – Traffic Operations • 617.973.7967 • Andrew.Paul@state.ma.us • Joe Frawley • MassDOT District 3 – Traffic Engineer • 508.929.3916 • Joseph.Frawley@state.ma.us