Triangle Project FAQs
General Triangle Project Information
Construction Information
Navigating the Roundabouts after Construction
General Triangle Project Information
This project was initiated in the late 1990s as a minor project to improve the operations and safety at the intersections of Main Street/Cemetery Road, Main Street/Scioto Darby Road, and Cemetery Road/Scioto Darby Road. Since these three streets form a triangle in the center of Hilliard, the project was commonly referred to as the “Triangle Project”.
In the past 10+ years the project has grown in complexity and the project limits have been extended beyond these three intersections, but the name has stuck. A map showing the limits of the Triangle Project is shown below. The project area and scope was modified over the years to address the long range needs of motorists and pedestrians in the area as traffic volumes increase due to growth to the west.
Hilliard Triangle Project Limits

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The project consists of two roundabouts on Main Street at the Cemetery and Scioto Darby Road intersections and two traffic signals on Scioto Darby Road at Cemetery Road and at Bradford Drive. Cemetery Road and Main Street will have two lanes in each direction. On Scioto Darby Road, there will be two lanes in each direction west of Cemetery (in front of Memorial Middle School) and one lane in each direction east of Cemetery Road.
The existing “jogs” in the roadways through this corridor will be corrected. For example, the sharp deflection of the streets at the Cemetery Road and Scioto Darby Road intersection (near the corner of Hilliard Station Sixth Grade School) will be eliminated and will be replaced with a smooth curve that meets current design standards. As a result, the STOP condition on Scioto Darby Road (westbound), which is difficult to maneuver due to the sharp angle and poor visibility, will be replaced with an intersection at a nearly 90 degree angle.
An outlined footprint of the future streets over an aerial view is shown below.

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The Triangle Project includes completely new pavement, curb and gutter, sidewalk, multi-use paths, enclosed storm sewer, underground storm water quality units, street lights, two traffic signals, waterline, signage, pavement marking, school zone flashers, overhead flashing lights at the school crossings, landscaping, and irrigation.
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The decision to install roundabouts was not an easy one. When the idea was brought forward for consideration in 2004, the design of an improvement that included traditional signalized intersections with widening was nearly complete. At that time, the first major roundabout in Ohio (Dublin) had recently opened, so there was a hesitancy to try something so new in such a critical location.
However, the results of a roundabout feasibility study demonstrated that the merits of roundabouts significantly outweighed the merits of the traditional signalized intersections.
- Roundabouts are designed to move traffic through an intersection at a slower speed but steady rate, increasing safety. Studies from around the world show that roundabouts typically reduce crashes by 40-60 percent compared to stop signs and traffic signals. They also reduce injury crashes by 35-80 percent and virtually eliminate incapacitating injury and fatal crashes. Two recent U.S. studies are consistent with these results.
- Under the traditional signalized intersection scenario, the intersections would be very large due to the need to install multiple turn lanes on each street to accommodate all the turning traffic. Large intersections create an environment that is conducive to high vehicular speeds. With the roundabouts, there are fewer lanes of traffic because there are no turn lanes.
- The pedestrian environment is much safer with roundabouts. Intuitively this may not initially make sense because pedestrian WALK/DON’T WALK signals are removed at roundabouts; however, large intersections with wide pavements to cross, many turn lanes, and higher speeds do not provide an environment that is inviting or conducive to pedestrian mobility and safety. Even with the WALK/DON’T WALK lights at signals, turning vehicular traffic does not stop and pedestrians are at risk in the crosswalks due to higher speed vehicles making turns. The City of Hilliard wants to increase the number of pedestrians in the Triangle area with this project. Pedestrian mobility is not improved by widening roadways and increasing vehicular speeds; pedestrian mobility is improved by changing the environment to slow vehicles, shorten pedestrian crossings, and encourage more pedestrians. Roundabouts provide these pedestrian benefits; traditional widening with signals does not.
- Roundabouts slow traffic but the overall intersection delay is significantly less than in a signalized intersection. Even though traffic signals are common at managing traffic, they are very inefficient because much of the traffic is stopped at any given time.
- Traffic back-ups are greater with traffic signals than roundabouts. Because some traffic is always stopped at a traffic signal, traffic queues can get long. With the roundabouts, some back-up traffic is anticipated during peak periods, but the back-ups will be less than with a traffic signal.
- Nearby properties are more accessible under the roundabout scenario. Left turns into and out of driveways close to major intersections cause safety and operational problems. Medians were planned in both the roundabout and signal alternatives. However, U-turns are permitted at the roundabouts. Therefore motorists can get into and out of most properties by making right turns at driveways and U-turns at the roundabouts.
- Roundabouts are more environmentally friendly than signalized intersections because there are fewer idling cars which reduces air emissions and less power consumption with no traffic signals to operate.
- Roundabouts operate more quietly than signalized intersections by reducing stop-and-go traffic and associated engine noise.
- Roundabouts provide an opportunity for a community focal point by placing landscaping or signature art in the center of the roundabout. Roundabouts manage traffic with less pavement which makes a more aesthetically pleasing streetscape.
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The outside diameter of the Main Street/Cemetery Road roundabout is 160 feet. The outside diameter of the Main Street/Scioto Darby Road roundabout is 175 feet. The Scioto Darby Road roundabout is larger in order to accommodate the skewed angle that Scioto Darby Road creates when it intersects Main Street.
For comparison purposes, the two-lane roundabouts on Britton Parkway in Hilliard are 180 feet in diameter; the single-lane roundabout on Leap Road is 160 feet in diameter.
Intuitively, it may seem that the two-lane roundabouts planned for Main Street are too small. However, roundabouts cannot be designed using a one-size-fits-all approach. The context of each setting is important in achieving a safe and efficient roundabout design. An iterative approach is typically used in the design of roundabouts; capacity (larger circles/higher speeds) and safety (smaller circles/lower speeds) are balanced on a case-by-case basis.
The Main Street roundabouts were designed to accommodate school buses, emergency vehicles, and tractor-trailers, but they were kept as small as possible to maximize vehicular and pedestrian safety. The smaller footprint also minimizes the impact on adjacent properties. It is important to note that when large tractor-trailer type vehicles travel through the roundabouts that they must occupy both lanes. Because of this, drivers should never try to pass or travel adjacent to a large truck or emergency vehicle in the roundabout. Cars and school buses can travel simultaneously through the roundabouts because buses do not have separate trailers that track independently of the cab.
Some motorists confuse roundabouts with the older rotaries that have been around for a half century or longer. These larger circular intersections were removed from the engineer’s “toolkit” decades ago because they resulted in higher speeds, unsafe weaving operations, and more accidents, especially at high traffic volume locations. Motorists will see these rotaries in the center of small towns across America, but these rotaries will not accommodate large volumes of traffic in a safe manner like roundabouts do.
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This is one of the questions that the City of Hilliard gets the most from the public because it seems like traveling through one roundabout would be a simpler operation than traveling through two roundabouts. However, when we look at safety, operations, layout, access to businesses and schools, impact on property, and constructability, the single roundabout scenario has some serious drawbacks.
In 2007, the City of Hilliard evaluated the feasibility of installing one large roundabout in lieu of the two-roundabout scenario. The reasons why one roundabout is not recommended are:
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Size. A single roundabout would need to have three circulating lanes to accommodate all the traffic that would travel through the intersection. With two roundabouts, the traffic is distributed between two intersections that are smaller.
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Speed. A larger circle results in higher speeds. Roundabouts should be designed to accommodate traffic traveling at approximately 20 mph, and this speed criterion cannot be met with a large roundabout.
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Pedestrian impacts. With a single large roundabout, many of the entering and exiting approaches need to be three lanes to accommodate all the traffic. This results in longer pedestrian crossings and higher speed. The double roundabout scenario provides for a much more pedestrian-friendly environment than the larger single roundabout does.
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Impact on existing properties. The single roundabout scenario would result in significantly more property acquisition than the double roundabout scenario. In addition to the elimination of the Donatos business, the Hilliard Station Sixth Grade School, the Hilliard United Methodist Church, and the Walgreen’s business would be significantly impacted if a single roundabout were installed.
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Complicated operations. If one large three-lane roundabout were installed at the Hilliard Triangle, this roundabout would likely be considered the most complicated roundabout in the United States with five major streets intersecting the roundabout in an urban area with high pedestrian use. This “5-Legged Octopus” is not what the City envisions in the center of our community.
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Maintenance of traffic during construction. With the installation of two roundabouts, east-west traffic can be maintained via Cemetery Road when the Scioto Darby Road roundabout is constructed (and vice versa). However, if the single roundabout scenario is pursued, it is much more difficult to maintain east-west traffic through the work zone during construction resulting in greater inconvenience to motorists traveling to and through the area.
A schematic drawing of the single roundabout scenario, which the City of Hilliard is not pursuing for the above reasons, is shown below:

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Construction Information
Underground utility relocation work by private utility companies (electric, gas, phone, telecommunications) is ongoing and will continue into the spring of 2010. Some of this private utility work will result in short term roadway closures, particularly along Scioto Darby Road, south of Donatos.
Construction will begin on the City’s portion of the project in May 2010. Work will continue through the fall of 2011.
Phase 1 (Summer 2010)
During the summer of 2010, the City’s project and work by AEP to relocate poles and overhead lines will take place concurrently. AEP will be working along the west side of Main Street near the Hilliard United Methodist Church and along Scioto Darby Road near Donatos and in front of Memorial Middle School during this time. The City’s crews will be working at the Main Street/Cemetery Road intersection. The City and AEP are working together to minimize the disruption to the public. Scioto Darby Road will be open for east/west traffic during this time; Cemetery Road will be closed. Roadway work surrounding Hilliard Station Sixth Grade School is expected to take place during this phase. The goal is for this work to be complete by the time school starts in late August 2010.
Phase 2 (Fall 2010)
During the fall of 2010, the section of Scioto Darby Road near The Arbors will close to construct the signalized intersection of Scioto Darby/Cemetery.
Phase 3 (Fall 2010 – Spring 2011)
Beginning in the fall of 2010, the City’s crews will be working at the intersection of Main Street/Cemetery Road.
Roadway work surrounding Memorial Middle School is expected to take place during the summer of 2011.
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Most construction projects are frustrating to motorists, pedestrians, bicyclists, businesses, and residents. It is impossible to build a multi-million dollar roadway project without aggravating some people along the way. This being said, the City of Hilliard has planned this project in phases to minimize the impact on motorists, non-motorists, and adjacent properties.
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The contractor is required to maintain pedestrian walkways during construction. The contractor is required to schedule work to minimize the amount of time that walkways are disturbed, especially during the school year. If a sidewalk is removed, walkways are to be designated in another area located within close proximity to the closed walkway.
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North/south vehicular traffic on Main Street will be maintained throughout most of the project. There will be a short-term (several days) closure of Main Street near Dairy Queen to construct portions of the street near the overhead arch structure. The City hopes to limit this work to a weekend when traffic volumes are less. During this period, traffic will be detoured via Madison Street and Grace Street.
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When the Main Street/Cemetery Road roundabout is being constructed, through east/west traffic will be detoured to Scioto Darby Road. When the Main Street/Scioto Darby Road roundabout is being constructed, through east/west traffic will be detoured to Cemetery Road.
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Traffic will be maintained to all businesses, residences, and schools. At least one driveway will be open to each property at all times. When driveways or streets are closed, the City will be provide directional signage on orange signs within the work zones to direct motorists to the appropriate entrance to each business.
The current planned construction phases of the project are as follows:

Phase 1: Cemetery/Main Roundabout (Cemetery closure): June 2010 – August 2010
Phase 2 & 3: Scioto Darby reconstruction and Scioto Darby/Main Roundabout (Scioto Darby closure): September 2010 – May 2011
Phase 4: Scioto Darby widening west of Cemetery (traffic maintained – no closures): June 2011 – August 2011
The project is expected to be fully complete by November 2011.
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Access will be maintained to schools and businesses at all times; however, the access may temporarily change throughout construction. Signs will be posted directing motorists to the open driveways.
There may be occasions when a roadway is closed to through traffic, but it is open to local businesses. For example, when Cemetery Road closes to through traffic during Phase 1, patrons will still be able to get to Jiffy Lube, Key Bank, Luigi’s Pizza, etc.; however, they will need to access these businesses from the east only. Access to and from Hilliard Station Sixth Grade School will be from the west only during Phase 1.
Access will never close to a business unless it is during non-business hours. We encourage residents to continue to support these local businesses during construction.
Construction is always a challenge and frustration for everyone and the City is working to minimize the impact that the construction has on local businesses, schools, and the traveling public. This being said, this is a major construction project. Please be patient and allow additional time to get through this work area.
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Navigating the Roundabouts after Construction
School Crossing Locations at Roundabouts
Several crosswalks throughout the project limits have been designated as school crossings. While it is legal for pedestrians to cross at any of the crosswalks, those designated as school crossings will include special signing and marking to emphasize the crossings.
As shown in the exhibit to the right, four locations at the roundabouts are designated as school crossings. These crosswalks will include overhead flashing lights and school signing. The exhibit below shows a picture of some of the special provisions at the roundabout school crossings. The overhead flashing lights will also be provided at the unsignalized crossing for Scioto Darby Elementary School at the intersection at Heywood Drive.
School Crosswalk Features at Roundabouts
Students crossing at the roundabouts will cross one direction of traffic at a time. It will be easy to judge gaps in traffic since traffic is moving slower and traffic is only coming from one direction. Signs and pavement markings will indicate to motorists that they are to yield. On two-lane crossings, pedestrians should wait until both lanes of traffic stop before proceeding into the street and crossing into the center medians.
Pedestrians should always make eye contact with motorists to indicate their intent to cross. Studies have shown that the act of a pedestrian showing their intent to cross the street through eye contact and body language is one of the most important and most successful ways to get motorists to yield and to improve safety at crossings. The City of Waterloo, Ontario, Canada embarked upon an active campaign in 2009 to educate their pedestrians and motorists on the way to cross a roundabout. They used a very catchy song, Roundabout Dance, to communicate their message that pedestrians need to show their intent to cross through “point and cross”.
Splitter islands (center medians) will be provided in the center of the crossing to provide a pedestrian refuge area. These islands are wide enough to accommodate groups of students and/or students with bicycles. After students cross to the splitter islands, they should cross the opposite direction of traffic in the same manner. Separating the street crossing into two parts shortens the amount of time pedestrians are in the street, making the crossing simpler and safer.
Pedestrians will likely be able to cross the street much quicker than it takes them to cross the street today under traffic signal control with pedestrian lights. Today, many students do not want to wait for the pedestrian crossing lights, so they cross illegally against the lights. Some students don’t understand the meaning of pedestrian signals or they aren’t paying attention when they get the WALK signal. Roundabouts provide a safer, simpler crossing with less delay for pedestrians.
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Just like at a signalized intersection, motorists need to follow the signs and pavement markings to select the appropriate lane because every intersection is unique.
For the Hilliard Triangle roundabouts, left turn maneuvers are made only from left lane approach which becomes the inside circulating lane. Motorists should never make a left turn from the right approach lane (or outside circulating lane). If you need to make an immediate right turn into a driveway after circulating the roundabout in the inside lane, you should switch lanes after you’ve exited the roundabout. Never switch lanes while circulating through the roundabout.
The City of Waterloo, Ontario, Canada developed an interactive tool to help motorists and pedestrians understand the proper way to navigate a roundabout.
Other important rules of the road are:
Slow down
Pick your lane based on your destination before you get to the roundabout
Yield to pedestrians or bicyclists at the crosswalk
Yield to traffic already in the roundabout (both lanes)
Enter the roundabout counter-clockwise and maintain your lane
Exit the roundabout at your desired location – for two-lane exits, make sure you maintain your lane at the exit
Yield to pedestrians or bicyclists at the crosswalk
Switch lanes if necessary after you’ve crossed the crosswalks
Never pass or drive beside a large tractor-trailer truck in a roundabout
If an emergency vehicle approaches while you are in the roundabout, continue through the roundabout and pull over after you’ve exited – do not stop in the roundabout
The City of Hilliard teamed with the Mid Ohio Regional Planning Commission (MORPC) and several other local government agencies to produce an educational video on the Rules of the Road entitled “Keep in the Loop”.
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At busy intersections along a commercial corridor, medians are important to safety of motorists and pedestrians because they restrict left turns in and out of driveways. The medians eliminate the incidence of left-turning T-bone collisions at driveways and reduces rear-end collisions at both roundabouts and at signalized intersections.
One huge benefit for businesses and motorists of using roundabouts instead of traffic signals along a corridor is the ability to make legal U-turns at the roundabouts. In most cases, motorists can get into and out of every business in all directions through the use of the U-turn at the nearby roundabout. Motorists can safely get into and out of driveways without trying to make a left-hand turn across several lanes of traffic.
For example, motorists can get to and from Hilliard Station Sixth Grade School in all directions like this:
Click image below for access to Hilliard Station Sixth Grade School from the South

Click image below for access to Hilliard Station Sixth Grade School from the East

Click image below for access to Hilliard Station Sixth Grade School from the North
Click image below for access to Hilliard Station Sixth Grade School from the West

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The landscaping is placed so drivers can’t see across the roundabout. This is so drivers cannot see the headlights of oncoming vehicles at night. This gives drivers a clear indication that there is an obstruction in the roadway and that they cannot drive straight ahead. This also encourages drivers to slow down as they enter the roundabout because they do not have clear view of the entire roundabout.
As a driver, you should be looking to the left, not across the roundabout, to see what traffic is approaching. There is enough sight distance to see approaching traffic from the left but not so much sight distance that drivers enter the roundabout at unsafe speeds.
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Having a traffic signal within close proximity to a roundabout does present some operational challenges. The City of Hilliard considered installing a third roundabout at the Cemetery Road/Scioto Darby Road intersection. While a third roundabout would have worked well from an operational standpoint, the property impacts on Hilliard Station Sixth Grade School and the challenges associated with providing access to the Arbors were too great.
Completely eliminating the portion of Scioto Darby Road (between Cemetery & Main), which would eliminate the intersection completely, was considered. Analysis showed that keeping this section of Scioto Darby Road open to traffic is critical because removing this roadway link would push more traffic to the Main/Cemetery intersection, thereby overloading that intersection and resulting in the need to have three circulating lanes. In order to make the Triangle intersections operate as they are intended, traffic needs to be distributed through two intersections rather than overloading one.
To minimize the likelihood that traffic will back up into the roundabout from the Cemetery/Scioto Darby intersection, the design of the traffic signal was refined to allow the signal to respond to changing traffic needs. Advance vehicle detection will be provided for westbound traffic on Cemetery Road (see L-4 and L-5 in the diagram below); if traffic backs up and sits on these detectors, the traffic signal will “switch to green” for Cemetery Road traffic. Also, there are no turn lanes on Cemetery Road or Scioto Darby Road, so the traffic signal will run much more efficiently because the “green arrow” phases are unnecessary.

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