Roundabout, Solution To Florida’s Population and Traffic Growth
Dear Friends & Neighbors,
(Please click on red links & note magenta)
It is wonderful that Florida is such a popular state that in the past decade, Florida’s population grew by roughly 680 people per day. As it turned out, according to a report in 247wallst.com, migration accounted for majority (92%) of Florida’s population growth, one of the highest migration rate in USA.
According to the U.S. Census Bureau, Florida overtook New York as the third most populous state in the country in late 2014. Since then, the population gap between the two states has only increased. Between July 2014 and July 2015, Florida’s population grew by 1.8% to 20.3 million. Over the period, New York’s population only grew by 0.2% to 19.8 million.
This certainly helps to explain why a drive to the Y, for me, which used to take 15-20 minutes (ten years ago) now often takes half an hour (or more if it is during rush hours). Fortunately, our responsive local government of Orange County had been taking action to try to solve many different parts of our communities’ traffic concern. There had been multiple projects under construction:
- SR50 at Lake Pickett Rd: Construct a receiving lane on northbound lake Pickett Road (District 5)
- Turkey Lake Rd at Palmacia Blvd: Construct a U-turn lane on southbound Turkey Lake Road (District 1)
- Reams Road at Center Drive: Intersection improvements (Orange County District 1). Adding a left turn lane on Reams Road
- Kaley Ave. at Rio Grande Ave.:Intersection improvements (Orange County District 6). Adding a left turn lane on Kaley Ave.
- Saddler Road at U.S.441: Intersection improvements (Orange County District 2). Constructing east bound right turn lane on Saddler Road
But one upcoming project really caught my interest: Roberson Road and Windermere Road: Intersection improvements (Orange County District 1) are needed. Intersection traffic and accident data were collected and analyzed. Two types of intersection improvement concepts are being considered based on a detailed traffic analysis.
Two types of improvements being considered include a traditional intersection treatment which adds right and left turn lanes (INTERIM)
as well as future (ULTIMATE)
configuration adding turn lanes in all four quadrants and the other type of improvement is an urban roundabout 105′ in diameter.
Although Roundabout intersection design is not often seen in USA, downtown Windermere had been taking advantage of this design for many years. Since many of our Floridian new locals are from other states and may not be familiar with this traffic design, let’s take a look at the history and the mechanism behind this circular intersection design in which road traffic flows almost continuously in one direction around a central island.
The operating and entry characteristics of these circles differ considerably from modern roundabouts. In 1907 architect John McLaren designed one of the first American roundabouts for both autos and street cars (trams) in the Hanchett Residence Park in what is now San Jose, California . Widespread use of the modern roundabout began when the UK’s Transport Research Laboratory engineers re-engineered circular intersections during the 1960s. Frank Blackmore led the development of the offside priority rule and subsequently invented the mini-roundabout to overcome capacity and safety limitations. The design became mandatory in the United Kingdom for all new roundabouts in November 1966. This give-way requirement has been the law in New York state since the 1920s.
In the United States modern roundabouts emerged in the 1990s. Municipalities introducing new roundabouts often are met with some degree of public resistance, just as in the United Kingdom in the 1960s. Surveys show that negative public opinion reverses as drivers gain experience with roundabouts. A 1998 survey of municipalities found public opinion 68% opposed prior to construction; changing thereafter to 73% in favor. As of the beginning of the twenty-first century, roundabouts were in widespread use in Europe. For instance, in 2010 France had more than 30,000 roundabouts.
A “modern roundabout” is a type of looping junction in which road traffic travels in one direction around a central island and priority is given to the circulating flow. Signs usually direct traffic entering the circle to slow and to give way to traffic already on it. Because low speeds are required for traffic entering roundabouts, they are physically designed to slow traffic entering the junction to improve safety, so that the roads typically approach the junction radially; whereas rotaries are frequently designed to try to increase speeds, and thus have roads that enter the traffic circle tangentially. Because of the requirement for low speeds, roundabouts usually are not used on controlled-access highways, but may be used on lower grades of highway such as limited-access roads. When such roads are redesigned to take advantage of roundabouts, traffic speeds must be reduced via tricks such as curving the approaches.
The fundamental principle of modern roundabouts is that entering drivers give way to traffic within the roundabout without the use of traffic signals. Traffic circles typically require circling drivers to give way to entering traffic. Generally, exiting directly from the inner lane of a multi-lane roundabout is permitted, given that the intersecting road has as many lanes as the roundabout. By contrast, exiting from the inner lane of a traffic circle is usually not permitted without first merging to the circle’s outside lane. Vehicles circulate around the central island in one direction at speeds of 15–25 miles per hour (24–40 km/h). Direction is determined by whether traffic drives on the right- or left-hand side of the road. In left-hand traffic countries the circulation is clockwise; in others, it is counterclockwise. Multi-lane roundabouts are typically less than 250 feet (76 m) in diameter; traffic circles and roundabout interchanges may be considerably larger. Roundabouts are roughly the same size as signaled intersections with the same capacity.
To better understand the operation of roundabout design, I’ve gathered several videos for your viewing, below:
To summarize, How To Drive A Roundabout (information below is provided by INDOT, Indiana Department of Transportation:
- Slow down and stay in your lane
- Yield to vehicles already in the roundabout
- Obey one-way signs at all times
- Yield to pedestrians and bicycles if there is a crosswalk
- Wait for traffic in the roundabout, it has the right-of-way
- When traffic clears, merge to the right and continue to stay in your lane
- Continue through the roundabout until you reach your exit point. Avoid stopping in the roundabout
- Signal and exit to the right
- Left turns are completed by circling around the center island and then making a right turn to exit
Roundabouts can easily accommodate emergency and large-size vehicles. Drivers should behave in the same manner as they would on any other road if an emergency vehicle approaches: carefully move as far right as possible and, if necessary, stop until the emergency vehicle passes.
Benefits of a Roundabout:
- Roundabouts reduce the number of potential accident points within an intersection
- Up to 90% reduction in fatalities
- 76% reduction in injury crashes
- 30-40% reduction in pedestrian crashes
- 75% fewer conflict points than four-way intersections
Slower traffic speeds:
- Drivers have more time to judge and react to other cars or pedestrians
- Advantageous to mature and novice drivers
- Reduce the severity of crashes
- Keeps pedestrians safer
Efficient traffic flow:
- 30-50% increase in traffic capacity
- Improves traffic flow for intersections that handle a high number of left turns
- Reduces need for turn lanes
- No signal equipment to install and repair
- Savings estimated at an average of $5,000 per year in electricity and maintenance costs
- Service life of a roundabout is 25 years (vs. the 10-year service life of signal equipment)
- Traffic calming
- Aesthetic landscaping
- Reduces congestion
- Reduces pollution and fuel use
For more information about Indiana Department of Transportation (INDOT)‘s experience with roundabout, please feel free to contact: John Wright, Highway Design & Technical Support Director, Indiana Department of Transportation, 100 N. Senate Ave.N642, Indianapolis, IN 46204, 317-232-5147.
With the data such as that gathered from INDOT, I am surprised that Roundabouts have not swept through the country sooner. I imagine we will be seeing a lot more of them springing up in the future.
~Let’s Help One Another~
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