[The following page represents the information presented in Assoc. testimony a the public hearing on CPD1985-0001B, October 16, Rockville City Council. The green text is speaking notes. The black text is taken from electronic slides used during the presentation.]
In general, we have no objection to concepts:
However, we see a large potential traffic issue related to Tower Oaks density. While it seems like a cozy pocket, draw the traffic lines too narrowly and you miss an essential reality of critically clogged traffic infrastructure around the CPD.
The Tower Oaks CPD plan dates from 1987. The traffic impact plan dates from 1985. Points:
How accurate is this study?

Look at the map, our special concern is the eastbound Wootton Parkway traffic. There are few alternatives/outlets for this traffic flow. It mostly goes to the intersection of Wootton Parkway and Rockville Pike. MDOT has already declared this intersection critical. And just beyond it, on the same roadway, is the intersection of First St. and Viers Mill Rd., which MDOT has already declared a failed intersection. By any measure, the Tower Oaks build-out is going to send approx. 1000 more peak hour trips toward these intersections.
If/when these intersections fail, where are the outlets.
Looking at the numbers for the Wootton Parkway/Rockville Pike intersection
[Note: The 1985 traffic study was for the Westmont Development, which has since been renamed, Tower Oaks. Also, the study referred to the Wootton Parkway element of this intersection as Ritchie Parkway.]
1985 Tower Oaks Traffic Impact Study
Trip Generation - Peaks Hours [p. 16, Table 3, In/Out columns. summed]
4221 am 4116 pm
based on 1.78 & 1.66 ratesDirectional eastbound Wootton Pkwy.: 22%
[p, 16, Table 4]Peak Hour Trips at Intersection
[calculated: e.g. 4221 * 0.22 am]929 am 906 pm
Master Plan Capacity Estimate: 1154
[p. V-16, Table 11]Remaining Capacity
[calculated: e.g. 1154 - 929 am]225 am 247 pm
Residual Flow, 1985 Estimate
[p. V-16, Table 11]296 am 247 pm
Study Conclusion: D Level Service (on A-F scale)
[p. 26, Table 7]Master Plan quote: "… levels of service E & F are not acceptable traffic flow conditions." So this 15 year old analysis indicates we'll reach the threshold of unacceptable traffic conditions, at service level D. Still there are traffic analysis variations contained in the Master Plan for Planning Area 12 (the Tower Oaks area) when compared to the Traffic Impact Study.
Master Plan, Area 12, Variations with Traffic Study
1. Plan discusses various trip generation rates [p, V-13, Table 9]
Maximum rates suggested: 2.32 am 2.02 pm
25% More generated peak hour trips
2. Direction eastbound Wootton Pkwy.: 30%
[p. V-14, Table 10]Yields peak hour generation at intersection
[calculated]1266 am 1235 pm
Already more than the Master Plan capacity (1154)
By either of these alternative factors, this intersection will already exceed its capacity with the existing approved Tower Oaks CPD planning based on 15-year-old assumptions of residual traffic. This suggests a problem.
Further, looking at the trip analysis numbers submitted with the CPD amendment.
From CPD Amendment, Trip Analysis
Peak trip generation: 3767 am 3729 pm
With 22% directional estimate: [1985 Tower Oaks Traffic Impact Study]
At intersection: 829 am 820 pm
Remaining capacity: 325 am 334 pm
With 30% directional estimate:
[1985 Master Plan, Area 12]At intersection: 1130 am 1118 pm
Remaining capacity: 24 am 36 pm
Using the 22% assumption from the 1985 traffic study, maybe we squeak by. But using the 30% Master Plan assumption, only a very small capacity remains to accommodate all the existing residual traffic. This is not going to cut it.
We think there is a big looming problem here. When we presented these numbers to the Planning Commission, one member mentioned that this analysis suggests the CPD already has too high a density for the roads. We agree, but don't advocate changing the base density or penalizing this developer for a late build-out. However, this CPD amendment is an addition to the already expected bad conditions and is not necessary to pursue the existing approved CPD build-out.
One facet of the CPD process is the Council only gets one chance at getting this approval right. You can't change or withdraw this approval later. The applicant can, applying again for future changes if relevant. We also believe the CPD agreement gives you authority to require further traffic study (staging item IV, item 2) if "1) traffic problems have arisen, and 2) traffic generation trips from the planning area exceed those anticipated under the Plan."
In closing we urge further traffic study. I do so hesitantly because the study is not a solution and may not change the outcome. But moving now otherwise is really acting blindly.
Copyright © 2000, Hungerford Civic Assoc.
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Last updated: Nov. 13, 2000.