Alexander Road Bridge Over Amtrak s Northeast Corridor (NEC) West Windsor Township, Mercer County

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1 Alexander Road Bridge Over Amtrak s Northeast Corridor (NEC) West Windsor Township, Mercer County Old Bear Brook Road Existing Proposed Alexander Road Amtrak s Northeast Corridor North Post Road Wallace Road Woodmeadow Lane Emil Street Alexander Road 1

2 Alexander Road Bridge Over Amtrak s Northeast Corridor (NEC) West Windsor Township, Mercer County Alexander Road Traveling toward Roundabout Alexander Road View of Mark s Trackside Auto Center West Approach - View of Bridge Alexander Road - East Approach North Post Road - West Approach Alexander Road - East Approach Frontage Road - View From West Frontage Road - View of Retaining Wall Aerial View of Roundabout Frontage Road - View From East 2

3 WHAT IS A ROUNDABOUT? A modern roundabout is an unsignalized circular intersection engineered to maximize safety and minimize traffic delay. Over the last few decades, thousands of roundabouts have been installed in Europe, Australia and other parts of the world. Recently, they have gained support in the United States with states such as West Coast, Mid-West and East Coast, and more recently, New Jersey, getting experience with their use and design. Drivers in those states also are becoming comfortable with their use. In the cities and towns where roundabouts have been built, and even where the public has been hesitant about accepting them initially, roundabouts ultimately have been accepted enthusiastically because of the increased safety they provide, along with traffic calming, and aesthetic benefits. Depicted below is the roundabout replacing the Alexander Road - North Post Road Intersection. IN THE UNITED STATES, WHERE ARE ROUNDABOUTS? Interest in roundabouts has been growing in the United States. Several hundred are now in place. Roundabouts have proven to be particularly effective at intersections with large numbers of left turns. They are also effective at places with moderate to high entering traffic volumes, and at the ends of freeway on and off ramps. In addition, they offer special advantages at the intersections with more than four legs. Oregon Colorado Michigan 15 Radius Truck Apron 25 Radius Center Island Splitter Island Maryland Circulatory Roadway Sidewalk Colorado Kansas Florida 3

4 Recently Constructed Roundabouts in New Jersey Princeton University Campus Roundabout - Princeton Township, Mercer County 4

5 Rutherford Square Station Rutherford, NJ 5

6 NJDOT Conceptual Design Projects with Modern Roundabout Configuration Under Construction Crossroads Re-Development Area, intersection of Routes 73, 90, US 130, and Haddonfield Road, Pennsauken Township, Camden County Lambertville/Gateway - West Amwell Township, Hunterdon County Route 41 & Route 47 - Deptford/Washington Township, Gloucester County Route 322 & C.R Woolwich Township, Gloucester County Route 130 Corridor Study - Pennsgrove and Carneys Point, Salem County Route 322 & Rowan Blvd. - Glassboro Township, Gloucester County East Main St. & South Main St. - Bound Brook Township, Somerset County 6

7 Other Roundabouts in the US Rt-219 Scaggsville, Maryland 7

8 US-6 Avon, Colorado 8

9 Comparison between Modern Roundabouts and Traffic Circles ROUNDABOUTS ARE NOT TRAFFIC CIRCLES Roundabout Employs traffic calming characteristics. Entering traffic yields to circulating traffic, which always keeps moving. Very efficient with heavy traffic. No weaving distance is needed, so roundabouts are small and fit in compact spaces. Deflection controls speed without enforcement, thereby reducing accidents. Deflection forms gaps in traffic so other vehicles can enter. Flare promotes narrow streets between roundabout, saving cost and neighborhood impacts. Roundabouts are designed to require a speed reduction, often times to the mph range. Diameter is calculated based on traffic volumes and movements and are much smaller. Traffic Circle Circulating traffic can not clear when entering traffic fills circle Heavy traffic causes gridlock. Circles must be large to provide long weaving distances. Serious accidents can result on high speed streets. Fast entries impede gap acceptance and defeat the yielding process. Higher capacity requires wide streets between circles, wasting money and land. Traffic Circles are designed to maintain the prevailing roadway speed, often times 35 mph and up. Diameter is arbitrarily determined by the space available and is often very large, allowing higher speeds and unsafe conditions. Traffic circles are not pedestrian friendly within a community setting. New Jersey Department of Transportation has been maintaining a program for the past several years to eliminate obsolete traffic circles in New Jersey. 9

10 Myths and Facts about Roundabouts Myth Roundabouts cause longer commutes. Roundabouts are difficult to maneuver. Roundabouts are not safe for pedestrians. Fact Roundabouts keep traffic moving. The major delay on a person s morning or evening commute is usually the time spent sitting at traffic signals. Eliminating the need to stop and wait reduces delay. Using a roundabout is the much the same as making a "right turn on red." At a traffic signal, a right-turning driver stops at the stop bar, looks for conflicting traffic coming from the left, chooses an acceptable gap in the traffic flow, and then turns right onto the cross street. At a modern roundabout, the oncoming driver approaches the yield line, looks for conflicting traffic coming from the left, chooses an acceptable gap in the traffic flow, and then enters the roundabout with a right turn at the yield sign.once inside the roundabout, a driver continues circling counter-clockwise until reaching the desired exit. Exit maneuvers are also right turns. Roundabouts are very pedestrian friendly. The splitter islands provide a space for pedestrians in the middle of each crossing. Therefore, pedestrians only need to cross one direction of traffic at a time. The pedestrian crosswalks are set at least one full car length back from the yield line. That way, pedestrians do not have to cross in front of drivers that are looking for their gap in traffic. Experience has shown that the stopped vehicle one car length back from the yield line is more aware of pedestrians. Roundabouts cause more accidents than the stops signs or traffic signals that they replace. According to the Insurance Institute for Highway Safety, modern roundabouts reduce motor vehicle crashes. Their July 2001 Status Report noted "most serious kinds of crashes at conventional intersections are virtually eliminated by roundabouts Crashes that do occur tend to be minor because traffic speeds are slower." The study reviewed 24 intersections around the U.S. that have been converted from stop signs or traffic signals to modern roundabouts. At those intersections, all crashes were reduced by 39%. Serious crashes were reduced by 76%. At the time of the study, there had been no fatalities at any of the new roundabouts. So, the study estimates that fatal or capacitating injuries will be reduced by 90% at those intersections. 10

11 SAFETY AND OPERATIONAL PERFORMANCE How can such impressive accident reductions be explained? One reason is that there is a reduction in the number of conflict points within the facility. As the figure below shows, a standard intersection has 32 potential vehicle-to-vehicle conflicts versus 8 for a roundabout. In addition, modern roundabouts are designed such that traffic enters at nearly right angles to the circulating traffic. The merging lanes that characterized traffic circles (and led to confusion over who has the right-ofway) have been eliminated. Third, roundabouts are relatively small, particularly when compared with typical traffic circles. So, traffic speeds are slower, there are more opportunities to enter circulating traffic, and fewer accidents result. NAVIGATING A ROUNDABOUT Motor Vehicles Approaching and Entering the Roundabout When approaching the roundabout, follow the lane designation signs, slow down and yield to pedestrians in the crosswalk.look to the left. Traffic in the roundabout has the right-of-way. Approach the yield line and enter the roundabout when there is an adequate gap in the circulating traffic flow.if another car is waiting at the yield line ahead of you, do not stop in the crosswalk. Keep the crosswalk clear for pedestrians.bicyclists are permitted to ride within the roundabout. Please share the road and do not pass a bicycle in the roundabout. Conflict Point Illustration 11

12 Navigating a Roundabout Motor Vehicles Exiting the Roundabout Once you have entered the roundabout, proceed counter-clockwise to your exit. You now have the right-of-way. As you approach your exit, turn on your right turn signal. Exit the roundabout, yielding to pedestrians in the crosswalk. Trucks Drive on the circulatory roadway, except large trucks and trailers may use the truck apron provided to negotiate the tight turning radius. Drive (usually with just the rear wheels) on the raised pavement of the truck apron to navigate more easily. Cars should not use the truck apron. Emergency vehicles such as large fire engines can easily navigate the roundabout by riding over 15 inner truck apron. Pedestrians Stay on the designated walkways at all times. Cross only at the designated crosswalks. Never cross to the central island. Watch for cars; you have the right-of-way, but your best protection is your own attention. Cross the crosswalk one lane at a time, using the splitter island as a refuge area before crossing the next lane. Bicyclists You are strongly encouraged not to ride within the roundabout itself. Studies have determined that the safest way to proceed through a roundabout intersection is to walk your bicycle. If you are comfortable riding in traffic, take the lane and circulate like you are a vehicle, making sure you yield to traffic in the circle when entering. Ride at the speed of the circular roadway to discourage cars from passing you. When you exit the roundabout, use your right hand signal. If you are unsure about using the roundabout, dismount and walk your bike as a pedestrian at the designated crosswalks. 12

13 Crosswalk Treatments Brick Painted Crosswalk Street Print 13

14 Truck Apron Treatments Asphalt Brick Pavers Structured Asphalt Cobble Stone Stamped Concrete 14

15 Center Island Treatments Grass Island Landscaped Island Asphalt Island 15

16 Formliners (Retaining Wall Treatments) 16

17 Recommended Shrubs ABELIA X GRANDIFLORA Glossy Abelia CORNUS SERICEA FLAVIRAMEA Yellowtwig Dogwood CORNUS SERICEA SIBIRICA Tatarian Dogwood FORSYTHIA X INTERMEDIA SPECTABILIS Showy Border Forsythia ILEX VERTICILLATA Hybrid Winterberry ITEA VIRGINICA HENRY S GARNET Henry s Garnet Virginia Sweetspire PRUNUS LAUROCERASUS OTTO LUYKEN Otto Luyken Hybrid Cherry Laurel VIRURNUM TRILOBUM COMPACTUM American Cranberrybush Viburnum 17

18 Recommended Trees ACER RUBRUM Red Maple BETULA NIGRA HERITAGE Heritage River Birch CORNUS MAS Corneliancherry Dogwood CRATAEGUS PHAENOPYRUM Washington Hawthorn MAGNOLIA VIRGINIANA Sweetbay Magnolia NYSSA SYLVATICA Black Gum CRYPTOMERIA YOSHINO Japanese Cryptomeria PINUS STROBUS FASTIGIATA Columnar White Pine 18