Traffic Facts

Day 4: We need a 30-year solution!

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.aspx

This 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 day
Multi-lane roundabouts – 45,000 vehicles per day
2-lane road – 18,000 vehicles per day
4-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.html

Yet, 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, more development will happen, and more people will move in. Doesn’t this sound a whole lot like no-growth land use policies disguised as traffic engineering?

The fact of the matter, and what the special interests do not want to acknowledge, is that growth in this region is inevitable and currently that growth is happening in places we in Virginia have no control over – namely Frederick County, MD.

Now, let’s talk a bit about cost. What is the cost of a traffic signal vs. a roundabout? Per Mr. Joseph Kroboth, Director of the Loudoun County Department of Transportation and Capital Infrastructure (DTCI), he indicated that the cost of a traffic signal is approximately $750,000 to $900,000 versus a single-lane roundabout that starts at $8,000,000. Are we seriously going to spend $25,000,000 to $50,000,000 on the multiple single-lane roundabouts that the special interests advocate to install along the Route 15 corridor even though they would all be obsolete upon completion due to projected traffic volumes? Do we want to spend significantly more than $50,000,000 for a corridor of double-lane roundabouts, which will ultimately fail within 30 years and need to be ripped up and replaced with lights?

Why are we even considering wasting the County taxpayers and Region’s money on solutions that will fail? Again, the answer seems to be because the special interests would rather do that than allow for even the potential of additional growth in the area. They still think they live in the middle of nowhere and don’t want anything to change.

Fix Route 15 Now!

Comments Off

August 30, 2018

Traffic Facts

Day 3: New Jersey Suburban and Rural Growth – The Fate of Traffic Circles

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.

Comments Off

August 29, 2018

Traffic Facts

Day 2: Gilberts Corner and Traffic Calming

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

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, if they are forced to add them, small grass shoulders rather than paved ones.

Here is a link to an archive of the website of one group that advocates against widening (site is no longer active):

https://web.archive.org/web/20050124173205/http://catoctincoalition.com:80/.

Notice the picture at the bottom of their page which shows how they envision Route 15 North. It’s pictured here as well.

Although a pretty scene, does this narrow 2 lane road design with trees inches from the edge represent what you think Route 15 should look like? Do you think this design has even a remote chance of providing the capacity increase that we need? Is a tree lined road with no shoulders going to improve safety? The decision is yours.

Stay tuned as we continue our series of informative articles.

Fix Route 15 Now!

Comments Off

August 28, 2018

Traffic Facts

Day 1: Roundabout Facts and Route 15 Volume

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 signals.
Roundabouts are static. Traffic signals can adapt to significantly different traffic patterns, like traffic letting out after a concert or football game at a stadium.
Multi-lane roundabouts can be difficult in terms of design and operation. The delay and safety experience at a multi-lane roundabout is sensitive to small geometric characteristics.”

Ask yourself this question – does Route 15 have balanced flow from all sides or does it have a “heavy commuting pattern” with the vast majority of volume coming from one direction?

Now on to the numbers. According to VDOT’s 2017 volume numbers found here: http://www.virginiadot.org/info/2017_traffic_data_by_jurisdiction.asp, the traffic count on Route 15 around the Point of Rocks Bridge is 21,000 vehicles per day and 26,000 per day around White’s Ferry Road. Both are increasing every year. Mr. Spack provides the guidelines that a single lane roundabout can handle up to 25,000 vehicles. That is less than the current volume on Route 15 at White’s Ferry and will be less than the volume on the rest of the corridor by the time any project is completed. This means that large multi-lane roundabouts with a 45,000 vehicle capacity would be required at all intersections, if implemented.

Separate from roundabouts, He also mentions on another page: http://www.mikeontraffic.com/numbers-every-traffic-engineer-should-know/ the acceptable planning levels of daily capacity for several types of roads themselves. The two most pertinent ones are:

2 lane (w/ left turn lanes): 18,300 vehicles per day
4 lane (w/ left turn lanes): 36,800 vehicles per day

These numbers tell us that regardless of what type of intersections are installed between Leesburg and the Point of Rocks Bridge (i.e. traffic light or roundabout), expansion to 4 lanes is going to be required for the entire corridor in order to handle current volume.

We have also found this statistical analysis which draws the conclusion through regression analysis that the planning capacity of roundabouts is almost always overstated compared to actual results. https://www.sciencedirect.com/science/article/pii/S2095756416300563. One of the main challenges with roundabouts, and multi-lane roundabouts in particular is that driver behavior ultimately determines capacity and safety. One example of a problem situation lies just a few miles north of us.

The Google Maps satellite shows the roundabout on Route 15 in Maryland near the Point of Rocks Bridge. This is a multi-lane roundabout that the special interest groups love to point to as a success story. This roundabout has approximately 21,000 vehicle trips per day. Notice the semi-truck having to cross into the other lane in order to make the turn. Is this safe?

So, with all of this data in mind, what we have here is an idea proposed by the special interest groups – turn the Route 15 corridor into a series of roundabouts – that, at best:

still requires 4 lanes to handle the volume;
will not work based on the pattern of heavy north/south volume;
functions LESS efficiently than coordinated traffic lights; and
creates potential safety issues when semi-trucks and other large vehicles must cross multiple lanes at once in order to navigate through the roundabout.

The special interest groups also maintain, despite the volume numbers proving otherwise, that single lane roundabouts AND traffic calming measures throughout the corridor will keep traffic moving. This is simply a false narrative and they need to be called out on it.

Please visit us again tomorrow when we will explain how the Route 50 roundabouts and traffic calming measures around Gilbert’s Corner and westward are not representative of the situation on Route 15.

Fix Route 15 Now!

Comments Off

August 27, 2018

Traffic Facts

Route 15 – Weekday Vehicle Trips Grew by 10.5% at the Point of Rocks Bridge in 2017!

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!

Comments Off

August 24, 2018