Think the traffic in downtown Herndon is bad, just wait until 2025. A draft traffic study presented to the Herndon Town Council at a work session earlier this month predicts that even if the downtown area is only built up to what is already approved on the books, northbound Van Buren Street, during the hours of 5-6 p.m., would be the worst travel corridor in town. In addition, there would be a total of 36 networkwide signal phase failures, meaning the waiting vehicles failed to make it through the intersection during the green light, most along Van Buren Street approaching Elden Street and there would be several "hot spots," or problem areas, with long traffic delays throughout the area.
Now imagine what would happen if an additional 755,000 square feet beyond that was developed. How about another 1 million square feet above that?
At its worse, Alpha Corporation in conjunction with BMI, the company tapped to do the study, is predicting virtual gridlock with six primary travel corridors functioning with long travel delays to extreme delays potentially affecting other traffic patterns. In addition, there would be approximately 156 networkwide signal phase failures.
"We looked at the functionality of the primary travel corridors and then focused on hot spots identified as problem areas," said Jim Clarke, project manager for Alpha. "The objective is to provide information to assist the Planning Commission and Town Council for future development."
Besides identifying potential traffic impacts, the study suggests several minor improvements, ranging from adding turn lanes or traffic signals to realigning intersections.
"THE BIG ASSUMPTION of the study is that the comprehensive plan is not going to change," said Dana Heiberg, the town's senior planner, head of the comprehensive plan section. "We're not going to widen Elden Street to four lanes. … We're going to maintain the downtown character, the historic aspect. We're not going to widen or lengthen anything."
The study looked specifically at three scenarios for growth by 2025: the baseline, which presumed there would be no additional development or redevelopment within the study area beyond what has already been approved. Under this scenario, the traffic projections are based on the assumed growth rate applied to the sum of existing traffic volumes and additional vehicle trips expected from approved, but not fully developed sites.
Scenario A created traffic projections based on a total developed or redeveloped area of around 755,000 square feet of gross floor area within the downtown area. According to the study, this equates to approximately 283,000 square feet of gross floor area beyond the existing development.
Scenario B looks at a total developed or redeveloped area of around 1,076,000 square feet of gross floor area, or roughly 604,000 more square feet of gross floor area beyond current levels.
The study's findings do not, however, signal impending changes to the comprehensive plan, said Heiberg.
"It can be used in a number of ways. The council became interested in having it done to move forward with some downtown planning," Heiberg said. "It allows us to look at the future of the downtown. If certain improvements are made, certain densities will work well and some [of the suggested improvement] projects could become part of the CIP [capital improvements plan]."
THE STUDY SUGGESTS eight minor improvements as part of the baseline scenario, an additional three suggestions under scenario A and adds two more suggestions under scenario B.
The first eight include parking reconfigurations and curb lines on Lynn Street; the installation of a pedestrian activated traffic light at the W&OD trail crossing on Elden Street; east Elden Street improvements; another pedestrian light at the W&OD trail crossing at Van Buren Street; traffic signal installations, lane shifts and new turn lanes for Elden Street between Grace and Center streets; a right turn pocket on northbound Van Buren Street at Elden Street; the installation of a traffic signal, left turn only and a curb lane for the Grove/Monroe/Van Buren streets intersection.
Additional improvements under the higher volume scenarios focus on improvements at the Pines Shopping Center and on Elden Street at Monroe Street.
"When we went through this, we identified minor improvements that are do-able, reasonable improvements," Clarke said.
Some projects, such as improvements to Elden Street at the Center Street intersection are already part of the CIP, but are several years out, said Heiberg. What improvements, if any, that are completed would depend on if they require changes to the comprehensive plan, the need to purchase land or the destruction of a historic building.
Heiberg said the improvements might be classified as minor, but realigning an intersection, for example, is a major undertaking for the town.
"The improvements could also be part of negotiations with developers, voluntary proffers," Heiberg said.
The computer program used to generate the study will become the property of the town and could have future uses as development plans come before the town's various boards for approval.
"We can use it for rezonings. We believe we have the experts needed to keep the model alive," said Henry Bibber, the town's director of community development. "We can use it to project the appropriate densities. It can also model garage locations and shared public parking areas."
Highlights of the study are available on the town's Web site at www.town.herndon.va.us, under "What's New."