Traffic Facts

One key point that we at fixroute15now.com advocate is that the corridor needs a long-term solution. Given that many projects in the region are competing for the same project dollars, we must not waste our time and money on feel-good “solutions” that will not serve through this time period. We WON’T get a do-over. Since it will take the county at least 10 years to widen a 3.5 mile section of the Route 15 corridor, we must look at growth curves going out 40 years.The lower corridor today handles 26,000 vehicles per day (vpd). Kimley-Horn’s US Route 15 Congestion Report, dated May 18,2017, uses a 1.5% forecasted growth rate for the lower-end of the corridor (Battlefield Parkway to Montresor Road).  See Section 6: Traffic Forecasts (pages 25-26) of the report: https://lfportal.loudoun.gov/LFPortalinternet/0/doc/218963/Electronic.aspxThis is a conservative estimate considering volumes have been increasing by 3% per year for the last 5 years and spiked at 10% growth during 2017 – the last year for which records are available. We’ll say for the sake of argument that actual annual growth for the next 40 years will average somewhere between those two numbers. The chart below shows what that volume increase for the Lower Corridor will look like at different rates of growth: What this chart tells us is that at even the most conservative growth rate estimate, 47,000 vehicles (predominately North-South traffic) will travel the Route 15 Lower Corridor on a daily basis at the end of the project’s lifespan (Phase I).As for the Northern half of the corridor, Kimley-Horn will publish their projections in the next Safety & Operations Study, anticipated to be released in September. While we’re waiting for them, let’s use the same rates of growth from the first chart on the current volume of 21,000 vpd at the Point Of Rocks Bridge: Keep in mind the following previously established maximum capacities:Single lane roundabouts – 25,000 vehicles per dayMulti-lane roundabouts – 45,000 vehicles per day2-lane road – 18,000 vehicles per day4-lane road – 37,000 vehicles per day From this information, we can reasonably conclude several things:Single-lane roundabouts will fail the Lower Corridor NOW even under CURRENT volumes.Single-lane roundabouts will fail the Northern Corridor by the time they are completed.Multi-lane roundabouts will fail the Lower Corridor within the project lifespan.Multi-lane roundabouts will fail the Northern Corridor within the project lifespan under all but the most conservative growth estimates.The entire corridor will fail without widening to 4-lanes and the Lower Corridor could eventually need more than that. Let’s hope that by 2057 there is a new Potomac crossing bridge in the works to take the stress off of Route 15.These facts and capacities are NOT in dispute. Even one of the special interest groups’ website acknowledges the ~25,000 vpd capacity of single lane roundabouts: https://web.archive.org/web/20050207120921/http://catoctincoalition.com:80/FAQs.htmlYet, they still advocate for such a solution for the corridor even though they know it will fail. Why? Well, the main point of argument that they make is that widening the road will mean that more vehicles will use it,…

The state of New Jersey, the Garden State, was once the garden spot to slightly more than 100 traffic circles at one point.  It was an idea that had originally served its purpose well – way back in the 1920s! However, starting around the 1970s, New Jersey began phasing this type of road design out as populations grew. In fact, there are only a few traffic circles left today. The primary reason for their elimination was that the increased number of drivers on the roads resulted in traffic circles being more likely to hinder traffic flow than ameliorate traffic congestion. Moreover, the increased number of vehicles and faster traffic speeds made traffic circles even more dangerous and accidents more frequent. So one has to ask themselves, why are the special interest groups advocating for roundabouts rather than widening on Route 15 North, when they know that those roundabouts pose significant safety challenges to our families AND STILL fail to address traffic congestion given the massive North-South traffic flow on Route 15? The answer is quite simple – roundabouts are now being heralded as a “traffic calming” mechanism.  Traffic calming is the code word for further reducing capacity by lowering the speed limit to approximately 10-15 MPH in the roundabout on a road that has vehicle volumes at almost 300% of what Route 15 was engineered to handle back in the late 1940s to early 1950s. As we’ve shown the last two days, roundabouts by themselves are woefully inadequate to address the massive North-South traffic flow on Route 15. In summary, the special interest groups’ mantra has been oft repeated as one for improving safety, access and flow. However, their advocacy for single lane, “traffic calming” roundabouts with no widening really results in increasing congestion since this type of roundabout cannot accommodate more than 25,000 vehicles per day – a number that is below the current day 26,000 vehicles per day in the 3.5 mile stretch of Route 15 between Battlefield Parkway and Montresor Road. It is a safe bet that in 10 years when this project is completed, the daily number of vehicles will have increased substantially above the current day volume, further rendering the design obsolete before it is even constructed. Whether a traffic circle or roundabout, the daily number of North-South vehicles will make these designs obsolete. So again, one has to ask themselves, why are the special interest groups advocating for roundabouts that pose significant safety challenges to our families and school children with increased risks of accidents AND STILL fail to address traffic congestion? The answer is pretty clear; “People Die On Roads, Driving is a Dangerous Business!” Remember, the data and science do not support roundabouts on Route 15 – don’t be fooled by the hype!  It’s nothing more than “no-growth” hysteria masquerading around as science and transportation engineering.

Gilberts Corner is the intersection of Route 15 and Route 50.  For many years this was a signalized intersection until it was redesigned with three roundabouts in 2008.  One of the common refrains from the special interest groups is: The roundabouts at Gilberts Corner worked so let’s build them on Route 15 instead of widening. Below is a satellite picture of the Gilberts Corner intersection.First some volume numbers for the Gilberts Corner intersection:Route 15 – 14,000 Annual Average Weekday Traffic (AAWDT)Route 50 – 18,000 Annual Average Weekday Traffic (AAWDT)Source: http://www.virginiadot.org/info/2017_traffic_data_by_jurisdiction.asp Satellite picture of Gilbert's Corner Both Route 50 and Route 15 at Gilberts Corner are at or within the 18,000 vehicle per day capacity constraint for a 2 lane road. There are three key reasons why the three roundabouts work (for now) at Gilberts Corner:1.      Balanced Directional Volume - The intersection has near equal volume coming from all directions (unlike Route 15 North). Having balanced directional volume is a key part of Mr. Spack’s research on successful roundabouts that was cited yesterday.2.      Three Roundabout Design – The three roundabout design allows vehicles to be dispersed and follow the path of least resistance.  For example, the roundabout at Howsers Branch Drive allows some Westbound Route 50 volume to avoid the main roundabout and head south on Route 15. See the red arrow above. This three roundabout design is neither an option on Route 15 North nor has it been proposed by the County. It is simply a non-starter.3.      Usage of 4 Lanes of Travel - The AAWDT traffic count of 32,000 for the combined intersection is NOT handled by a 2 lane road with a roundabout as the special interests would have you believe. There are 2 lanes on Route 15 as well as 2 lanes on Route 50. If we include the Howsers Branch cutoff, there are 6 lanes in play at this intersection.The three roundabout situation at Gilberts Corner, while effective for now, is in no way a comparative situation to what exists on Route 15 North of Leesburg.The second argument that the special interest groups make is that traffic calming measures similar to those created on Route 50 through Aldie and further westward, when combined with roundabouts, will completely solve the problems on Route 15 North. The problem with their argument and what makes it irrational is simply this – The traffic volume on Route 50 through the Aldie/Middleburg area is less than 10,000 AAWDT. Route 15 North handles 250% more volume! Even though we have shown traffic calming “solutions” to be completely irrelevant to Route 15 North, we do want to make sure everyone understands what the special interest groups mean when they tout this supposed solution. Traffic calming as the special interest groups envision for Route 15 North includes not only single lane roundabouts (which we’ve already shown will not handle the current traffic volume) but also trees on both sides of the road as well as in a median, even slower speed limits, limited sight lines, and maybe,…

Roundabouts are a hot topic when it comes to the discussion of Route 15 improvements. Some groups would have you believe that just installing a roundabout at White’s Ferry Road would solve all the problems of the Route 15 corridor. They will also put forward plans that would turn Route 15 from Leesburg to the Point of Rocks Bridge into a series of roundabouts while placing obstacles, trees, and other impediments in places that would force vehicles to slow down in order to navigate through the corridor and avoid running into something. This is also known as “traffic calming”. We will address these two items separately.First, some background. We at fixroute15now.com are a data driven, fact-based group and we will acknowledge the road engineering science of why some roundabouts work at certain intersections. There are real-world benefits to well-constructed roundabouts in the right locations. The challenge faced by many looking for a non-biased view of where and when roundabouts work is that most, if not all, readily available sources are either 100% for or against roundabouts. The vast majority of studies are also based on lower capacity single lane roundabouts rather than the higher capacity, multi-lane examples.We did manage to find Mr. Mike Spack, PT, PTOE. He is a traffic engineer with many years of experience and a supporter of roundabouts. You can read his bio here: http://www.mikeontraffic.com/about/. His website, mikeontraffic.com, is a great source for balanced information regarding the use of roundabouts. http://www.mikeontraffic.com/why-build-roundabouts/ explains in detail the approach to building as well as positives and negatives of roundabouts. He mentions (our emphasis highlighted):“Research suggests a single lane roundabout can accommodate up to 25,000 vehicles per day. A multi-lane roundabout with two entry lanes can accommodate up to 45,000 vehicles per day. Like other traffic engineering tools, a roundabout works better with certain characteristics. The ideal conditions for a roundabout are:Balanced traffic flow between all four legs. An unbalanced intersection with 90 percent of the volume on the major street may not see the same benefits as other more balanced locations.High left turn movements. Left turns, and U-turns, are accommodated extremely well by a roundabout.High crash history. Roundabouts can help reduce the severity of crashes and sometimes the overall number of crashes.Complex geometry. A roundabout can often accommodate more than four legs and/or skewed intersections better than stop signs or a traffic signal.”On this same page he also lists the major drawbacks of roundabouts:“There are no silver bullets in transportation planning and engineering.  Roundabouts are a better choice than traffic signals at most locations, however there are a few limitations the design engineer should consider:There may not be enough room to build the roundabout.A corridor with a heavy commuter pattern (most vehicles going one direction in the morning and then returning in the evening) can sometimes provide less delay with coordinated traffic signals.The overall distance pedestrians need to walk is often longer around a roundabout than a traffic signal controlled intersection.More difficult for visually-impaired pedestrians to cross compared to traffic…

The 2017 Virginia Department of Transportation (VDOT) data for Loudoun County is in: http://www.virginiadot.org/…/2017_traffic_data_by_jurisdict… The Annual Average Weekday Traffic (AAWDT) for the Virginia side of the Point of Rocks Bridge in 2017 was 21,000. Weekday vehicle trips grew by 10.5% (i.e. 2,000 vehicle trips) in 2017. Weekday vehicle trips for the last five years are as follows: AAWDT (VDOT Link ID 090018 - Lucketts Road to the Maryland State Line) 2017 21,000 2016 19,000 2015 19,000 2014 18,000 2012 18,000 Note, AAWDT for the lower part of the corridor in 2017 was 26,000 weekday vehicle trips. Vehicle growth continues on Route 15. There are no shoulders or widening proposed north of the Village of Lucketts. There is neither a timeline nor funding for the concept designs that are proposed north of Montresor Road. We will have to wait 10 years before we have four lanes from Battlefield Parkway to (or beyond) Montresor Road (only 3.5 miles). Imagine what the weekday vehicle trips will be in 10 years. Fix Route 15 Now!