Last week representatives from Gorove/Slade Associates presented the final Transportation Impact Study (TIS) before a public meeting of the MAG (McMillan Advisory Group). The audience was asked to submit any questions they had on the report and/or presentation; below are the responses from Gorove/Slade.
1. Who paid for this meeting?
The event was a regularly scheduled monthly meeting of the MAG (McMillan Advisory Group); CulturalDC and Gorove/Slade are both consultants under contract with Vision McMillan Partners (VMP), so all costs related to their attendance are paid for by VMP.
2. Who do the speakers work for?
The two speakers on public art for CulturalDC and the two speakers on transportation work for Gorove/Slade Associates.
3. How do you determine and define if traffic is detrimental?
Transportation Impact Study’s (TIS) performed for PUD applications, such as McMillan define ‘detrimental’ traffic as a condition where unacceptable levels of congestion occur at an intersection in future projections, which includes traffic generated by the project in question, and where unacceptable levels of congestion do not occur at the same intersection in future projections that do not include traffic generated by the project.
Gorove/Slade prepared two future traffic models that analyzed traffic congestion at a set of intersections adjacent to and near the McMillan site. One model included traffic generated by McMillan and future planned projects, the second model included only future planned projects. Analyses of traffic congestion are performed in both models and a ‘detrimental’ impact was determined when an intersection in the future model with McMillan traffic showed unacceptable levels of congestion where it did not in the future model without McMillan traffic.
4. Have small European style traffic circles been considered as an alternative to traffic lights?
Yes, other solutions to the new traffic signals proposed in the TIS were considered, including traffic circles. Implementing traffic circles as an alternative to traffic signals would require right-of-way widening at all four corners of each intersections in order to create the circle. This would require the taking of land outside of the McMillan PUD, making implementation of traffic circles unfeasible.
Smaller traffic circles, also known as mini-roundabouts, may be implemented in smaller spaces as an alternative to stop signs, but not traffic signals. There are locations where these alternatives may be feasible in or near the McMillan site; however the TIS did not conclude they were necessary to mitigate traffic impacts generated by the proposed development. Gorove/Slade did not recommend mini-roundabouts on the internal roadways in McMillan in order to show preference for pedestrian traffic – all-way stop signs have cars stopping for pedestrians, whereas mini-roundabouts only require cars to yield to pedestrians.
5. How many more cars over this mean in my neighborhood? How many projected cars because of development?
The amount of vehicles per hour generated by the development in the morning and afternoon weekday and Saturday peak hours are shown in Tables 6 (pg. 25) and 7 (pg. 29) of the TIS. The morning weekday peak hour traffic generated is 1,895 cars per hour or about one new car every 1.9 seconds. In the weekday afternoon peak hour, the development is projected to generate 2,061 cars per hour or 1 car every 1.7 seconds. The Saturday peak is 1,370 cars per hour or 1 car every 2.6 seconds. These cars will take various routes to and from the site, such that each major roadway approaching the development will have about 1 new car every 5 to 20 seconds during peak hours of demand.
The proposed McMillan plan contains 2,721 to 3,038 off-street parking spaces and 97 on-street spaces, so it has the capacity to accommodate that many vehicles coming to and from the site. Table 2 within the TIS breaks down the amount of parking provided per development parcel.
6. Left turns you are adding will cause more traffic in the Bloomingdale Neighborhood.
Any development of the site will create new traffic demand and some of that traffic demand will want to go south through the Bloomingdale Neighborhood. The McMillan TIS projects the development will increase traffic on First Street south of Channing Street by 1 car every 10 seconds during the morning rush hour, 1 car every 9 seconds during the evening weekday rush hour and 1 car every 17 seconds in the Saturday peak hour.
7. What other projects has Gorove/Slade performed a traffic impact study for? Have you ever followed up on the accuracy of these?
Gorove/Slade has performed traffic studies for many projects in the District and regional metropolitan area, including The Howard University Campus Master Plan, The Wharf (Southwest Waterfront Redevelopment) and National’s Park. Professionals working on the McMillan TIS are registered professional transportation engineers.
Typically, results of a TIS are not verified in the future because it is generally assumed that future projections of traffic are conservatively high. Instead, the methodologies used in the TIS are tailored to project a fair comparison between future conditions with and without the development. This allows traffic engineers to interpret the results and make conclusions on what impacts the development is expected to create. There are times when certain parts of a TIS are followed-up on, most often the projections of future traffic generated by the development. This is usually done to ensure the traffic generated by a development does not exceed certain thresholds (usually with the enticement that certain roadway improvements would be needed if traffic levels exceeded thresholds). Almost every time, the projections of future traffic are shown to be higher than the actual traffic generated by a development. This is because the methodologies that go into a TIS process always lean towards taking a conservative approach to estimating traffic – exaggerating traffic to get a better understanding of a development’s impact. For example, the traffic projections in the TIS assume that the development builds all of the parking requested in the application, and that it uses all of the parking supply constructed (i.e. no empty spaces in the parking garages). In addition, the traffic projections do not take into account trends showing a decline in traffic generation, and that the amount of vehicles generated will be the same in 2025 as today.
In the case of McMillan, there are simply too many variables that go into projecting traffic in the year 2025 to ensure an accurate result. Consider this, for the McMillan year 2025 projections to be completely accurate, the TIS would not only have to correctly model all McMillan traffic, but also the Armed Forces Retirement Home traffic, VAMC traffic, WHC traffic, among a lot of other variables.
8. Why do you have less total trips from each type than people in that type – for example, 60 AM trips for 146 townhomes?
Not every person living in an apartment or townhome will be an active part of the labor force, in other words working a job with traditional office hours and leaving within the same single hour as each other. With regards to the specific trips projected for the townhomes, Table 6 (pg. 25) in the TIS shows the AM peak trip generation for the townhomes as 74 in a single hour (28 transit, 6 walk, 2 bike, and 38 car), which is a very reasonable projection based on information collected national and regionally by the traffic planning and engineering industry. This assumption is further confirmed by Census information, where during the peak hour of traffic on North Capitol Street (7:30 to 8:30am based on data collected for the TIS) the amount of people in the labor force leaving for their jobs between 7:30 and 8:30 AM is 24.5% for the Census Tract where McMillan is located . Therefore, if you assume each townhome has two active people in the labor force (a conservative assumption), 24.5% of those workers would equate to 72 trips.
9. What are the total trips to and from the site weekdays and Saturdays, not just peak hours?
The same sources of information that provide trip generation estimates for the weekday peak hours may be used to calculate total weekday trips, however the TIS does not include this calculation because the methodology employed to convert vehicular estimates to multi-modal trips projections (see pages 22-24 of the TIS) cannot be performed to the same level of accuracy for total weekday trips. This is because the modal split used in the analysis is based on data collected for commuters, and is applicable to the weekday peak hours, but not necessarily for the entirety of a weekday. The modal split of development related traffic will differ during the day, and since the best modal split information is commuter based (census data and WMATA ridership survey), Gorove/Slade prefers not to replicate the calculations for weekday totals since it will only be at a lower level of accuracy.
There are fewer information sources for Saturday trip generation estimates, so Gorove/Slade did employ a methodology to calculate total Saturday trips before breaking the trips down by hour to determine the peak overall hour of McMillan Saturday traffic (see pages 26 to 28 in the TIS). The methodology is detailed in the TIS Study’s Technical Attachment B, which projects 22,794 total trips, of which 11,172 are vehicle. See Table 41 on (page 29) for the proposed development’s total Saturday estimate trips per mode.
10. Who tells us how this impacts our streets? Not in the development?
The McMillan TIS looked at impacts not just at streets in and adjacent to the development, but at a scope spanning over 18 intersections in the vicinity of the site. Given the time constraints of the MAG meeting on 3/13/14, Gorove/Slade spent more time discussing streets close to the site because there are more development-related impacts adjacent to the site. The TIS contains much more detail on impacts to intersections and roadways not adjacent to the site, such as Rhode Island Avenue and Georgia Avenue. For a full overview of the study area, refer to page 3 of the TIS – “Study Area Overview”.
11. How for south do your models look? As of now, when cars enter the Rhode Island Ave overpass, it bottlenecks all the way to the NY Ave underpass.
The study scope stretched from Georgia Avenue to the west, to Irving Street to the north, Rhode Island Avenue to the south, and the intersection of Michigan Avenue with Franklin Street to the east. The study scope area was set after discussions with the District Department of Transportation, with the intent that the study area encompasses all intersections where a detrimental impact of the development may be found. The farther away from the site, the less of a chance the development will have any impact on traffic. For example, the TIS shows that the McMillan development will constitute around 17-21% of future rush hour traffic at the intersection of Michigan Avenue and First Street, 7-8% at First and Rhode Island Avenue, and less than 1% at the intersections of North Capitol Street and Rhode Island Avenue.
12. Does the study address Traffic on N. Capital and 1st St south of Channing?
Yes, traffic on N. Capital and First St south of Channing St is within the study area.
13. Why did the report not include the Monroe Street development in the scope? Catholic and Trinity projects?
These projects are located outside of the study area prescribed by the District Department of Transportation so they are not specifically referenced in the report; however, the TIS analysis includes all traffic generating sources that are also contained in the 2040 Metropolitan Washington Council of Government (MWCOG) traffic model of the entire metropolitan DC area , which should include these projects.
14. Does your analysis of future traffic include known other PUDs or probable (empty or undeveloped properties) on the N. Capital Route or within a few miles?
The analysis includes all traffic generating sources that are also contained in the 2040 Metropolitan Washington Council of Government (MWCOG) traffic model of the entire metropolitan DC area. General information from the MWCOG model was combined with detailed information from developments within the study area to build the future traffic models. A discussion on this methodology starts on page 38 of the TIS.
15. Do you assess accidents and being more prone as part of this study?
The TIS contains a section that reviews crash data at intersections, including types of crashes (beginning on page 128). However, the traffic engineering industry has not yet developed a methodology to accurately predict how a development like McMillan will influence crash rates. Instead, the TIS qualitatively discusses intersections with high crash rates, possible reasons for the elevated rates are and how the proposed development may affect them.
16. Please address emergency and ambulance routes, vital concern with three hospitals.
The McMillan TIS does not contain a detailed review of emergency routes, as such an analysis would only be needed if the proposed development or any suggested improvements would eliminate any current route of emergency access. Since the proposed development will create additional emergency route options from new internal roadways that provide more connectivity to the existing network, the development is considered as having a beneficial impact to emergency traffic.
North Capitol Street
17. Why not extend North Capital and create two extra lanes from McMillan side – have two extra lanes?
There are several reasons why widening North Capitol Street is not recommended. First, the preservation and reuse of Cell 14 at the northeast corner of the McMillan site prevents widening North Capitol Street where it is closest to Michigan Avenue. Second, to get the most benefit (additional vehicular capacity) from widening a roadway, both sides of the intersection must also be widened. The intersection with the most capacity problems on North Capitol Street is its intersection with Michigan Avenue; since proposed development does not control the northern portion of this intersection, widening North Capitol Street would not provide congestion relief and may actually cause more congestion at the intersection as capacity funnels back to 6 lanes from 8. Finally, any widening of North Capitol Street to accommodate additional lanes would lengthen pedestrian crossings (~20 FT for 2 additional lanes), leading to a decrease in residential quality and safety.
18. The reason why no cars on North Capital is because they are on the other streets taking up space.
The issue of improper parking in designated residential zones is outside the scope of the TIS and should be reported to the DDOT and/or MPD.
19. Do you have any plans to replace residents parking along N. Capital to another area, e.g. offer them passes to the medical office building?
The TIS does not recommend and there are no plans to offer residents parking passes at the medical office building.
20. What if any considerations were made to ensure adequate egress for Stronghold residents, especially those trying to go south (left) onto N. Capital from Franklin? Girard is one way the other way.
It is true that turning left from Stronghold is difficult at times. The TIS addresses this concern in two ways. First, new internal streets within the development will allow more options for drivers to go to and from Stronghold. For example, if a left turn is not possible, a right turn followed by a quick left into the development and turning back towards North Capitol Street will be possible (it is not currently possible because left turns are not allowed from North Capitol Street to Michigan Avenue). Second, new traffic signals on North Capital Street will provide improved spacing between vehicles traveling on North Capital, facilitating more opportunities for left turns. In addition, as presented at the meeting, alternatives for how the new development’s street can connect with North Capitol Street are included in the TIS, such as connecting the Stronghold side of Franklin Street to the new traffic signal at the North Service Court.
21. Shortening left turn lane northbound at first and Michigan will cause major traffic backup on First.
The new parking garage entrance to Parcel 1 does impact this turn lane by making it shorter. However, the overall amount of left turns on to Michigan that may occur actually increases with all of the improvements recommended in the TIS. This is because geometric improvements at the intersection of First Street and Michigan Avenue allow for northbound and southbound left turns to take place concurrently (instead of sequentially, as they do now), which allows for the left turning traffic to get a longer green turn signal during each cycle of the traffic signal lights.
22. Extend extra lane on First ST to have two extra lanes.
The additional lanes recommended on First Street were selected in order to reach a balance between accommodating vehicular traffic demand, not encouraging more traffic to cut-through First Street, and not creating an indirect negative impact to other modes of travel (wider roadways can be detrimental to pedestrians and cyclists). For these reasons, Gorove/Slade does not anticipate recommending additional lane widening on First Street.
23. What is there to deter traffic leaving south service court from flooding down First Street?
The TIS does not anticipate a lot of traffic turning left from the South Service Court to First Street because the major traffic generators are located at the northern portion of the site and not along the South Service Court. In addition, the South Service Court does not extend all of the way through to North Capitol Street, which prohibits it from being an east-west cut through to North Capital Street. As described during the 3/13/14 MAG meeting, the new east-west internal streets, and how they connect to First Street and North Capitol Street were designed to entice more vehicular traffic to cut-through the McMillan development than to travel south on First Street.
24. Strongly recommend all way stop signs at Channing remain, to remove them would have a negative impact to public safety and traffic calming.
While the TIS’s recommendation to convert the current all-way stop to a one-way stop was based on traffic capacity analysis results showing a detrimental impact at that location, the improvement to solve the impact contradicts the general plan to use the new development’s internal streets to shift traffic from First Street to North Capitol Street. After hearing these comments expressed during the meeting, Gorove/Slade will discuss this concern with DDOT to consider altering the recommendation.
25. Channing and 1st Streets must have an all way stop.
See response to Question #24.
26. Strongly recommend restricting the use of 1st St below Channing any service trucks or delivery vehicles. Streets are only one way each direction. Also there is damage caused to structures by the rattle of large vehicles. Also, there is considerable pedestrian traffic and children playing.
First Street between Channing and Rhode Island Avenue is already restricted (by DDOT) to truck traffic . The proposed development will not use First Street as a truck route.
27. How many streets are planned to be constructed on the site?
The proposed development includes six new streets: (1), North Service Court, running east-west between First Street and North Capitol Street, (2) Evarts Street, running east-west between First Street and North Capitol Street, (3) South Service Court, running east-west from First Street to the community center, (4) Half Street, running north-south between Michigan Avenue and the South Service Court, (5) Three Quarters Street, running north-south between the Service Courts and (6) Quarter Street, running north-south between the Service Courts.
28. How much traffic do you estimate cutting through the site during peak hours? How do mitigate that?
On the east-west streets that cut through the site (North Service Court and Evarts Street), the TIS estimates they will carry a few hundred cars per hour during peak weekday hours. This is around the level of traffic currently carried on Channing Street. There are no plans to mitigate this traffic, as the layout of the new streets is intended to provide porosity and encourage drivers to take advantage of the new routes, which spreads out demand so it’s not concentrated on a fewer number of streets.
29. Are streets internal to the development (e.g. South Service Court) considered Public or Private? What are the implications for traffic management?
All streets will be open to public traffic and pedestrians at all times but privately maintained. The developer of the site will be responsible for their maintenance, and will also control how the on-street parking will be controlled (for example, meters versus residential parking).
30. The MAG would like to see the south lane of the South Service Court removed for safety reasons.
Gorove/Slade does not see any safety concerns related to the South Service Court’s southern lanes and does not recommend removing them. In addition, the South Service Court provides access and parking for the community center and public park.
31. If North Service Court is below street level of First ST, how will you connect two different levels of street?
The North Service Court will not be below First Street allowing the streets to connect and extend to North Capital Street.
32. How will this impact Bryant Street?
The TIS found the development will have no significant impacts to Bryant Street; therefore, there are no recommendations to change Bryant Street.
33. Will Channing Street be widened?
No, the TIS does not recommend widening of Channing Street.
34. Did you also look at below surface transit such as the Metro Brown line or only at surface transit- which will only contribute to more congestion (unless dedicated lanes, which DC hates).
The scope of a TIS for a development like McMillan only takes into account planned transit improvements that are documented and feasibly implemented by the study year (in this case 2025). The only improvements that fit this description are those documented in the North Capitol Street Line Study, DC Circulator Transit Development Plan and DC’s Transit Future System Plan (described on page 95 of the TIS). The reasoning: the development should not be able to take advantage of potential improvements that are not at least at a planning level. This is done to help identify potential transit impacts and recommendations, which could be understated if too many improvements were included in the study.
35. Are there plans for dedicated bus/bike lanes at least during rush hour?
See response to question #34.
36. Your discouraging cars by reducing driving, but what is being done to make public transportation more convenient and desirable?
The TIS recommends implementation of the recommendations made in existing transit planning documents: the North Capitol Street Line Study, DC Circulator Transit Development Plan and DC’s Transit Future System Plan. This includes the MetroExtra Route 80x, the Brookland-CUA Metro-Union Station Neighborhood Connector, the Tenleytown to Brookland Circulator Route and the Woodley Park/Adams Morgan to Brookland Streetcar line.
Locally, the study recommends taking advantage of the new traffic signals proposed, which will have signalized crosswalks (with ‘Walk’/’Don’t Walk’) signs, and consolidating/relocating transit stops to help riders cross the street.
37. Public transport doesn’t do much / isn’t convenient if the buses can’t go anywhere. People will be incentivized to use bus if the bus moves.
See response to question #36.
38. How do you envision pedestrians crossing the entrance to the medical facility when walking on the Olmstead Walk?
The Olmstead Walk in front of Parcel 1 along Michigan Avenue will direct pedestrians towards the crosswalk at the intersection of Michigan Avenue and Half Street.
39. Light considered on Douglas St. crossing N. Capital?
A pedestrian-oriented traffic light was considered at Douglas Street and North Capitol, but not included in the study recommendations. This is because the addition of any traffic operational control, such as a traffic signal, needs to balance the needs of adding access versus adding congestion and/or increasing crash rates. Any traffic control, from a stop sign to a traffic signal, can increase crash rates after installed (such as rear-end collisions at a traffic signal) and thus traffic engineers have a strict set of technical warrants that a new control needs to meet in order to be worthwhile. A pedestrian-oriented traffic signal at Douglas Street would not meet warrants, even considering future crossings generated by the new development. In addition, the new traffic signal at Evarts Street will provide a signalized option for pedestrian crossings approximately 300 FT away, providing an improved situation relative to existing conditions.
Non-Traffic Related Questions
40. Does your analysis account for idling times and new stops near residential?
The results of the traffic models do calculate idling and stops at the intersections included in the study area, but the study does not account for the non-traffic related impact of these stops.
41. This report does not include analysis of what impact the development’s additional traffic (cars and trucks) would cause to these intersections.
A structural analysis of traffic impacts is beyond the scope of the TIS and not within the area of expertise for Gorove/Slade. This question has been referred to the Structural Engineers.
42. How will traffic impact and affect structural integrity of existing structures?
See response to question #41.
 ACS 5-yr estimates, factfinder2.census.gov, Census Tract 33.01