An existing parking lot in Chapel Hill, located at the Chapel Hill Bible Church near the intersection of Erwin Road and Sage Road, is being proposed for rezoning. 241 existing parking spaces for the church are planned to be converted to park-and-ride lot spaces that will be used by University of North Carolina at Chapel Hill (UNC-CH) employees. Chapel Hill Transit will provide transportation from the park-and-ride lot to the UNC-CH campus. Figure ES-1 shows the general site location of the site. The project is anticipated to be complete by 2007. This report provides additional analysis to the original traffic impact study for this site for the full build-out scenario for the year 2008 (one year after full build-out), the no-build scenario for 2008, as well as 2006 existing year traffic conditions.
The proposed lot will have direct, full movement access to Old Sterling Drive and Erwin Road, using two existing church driveways. Figure ES-2 displays the preliminary site plan of the proposed park-and-ride lot and nearby roadways.
The site is located on the northeast corner of the intersection of Erwin Road and Sage Road at the Chapel Hill Bible Church property. Study area roadways include; Sage Road , Erwin Road, Weaver Dairy Road, Old Sterling Drive, Old Durham Road, Eastowne Drive, and US 15-501. Eastowne Drive, and its intersections with Old Sterling Drive and US 15-501 at Lakeview Drive are included in this addendum to the original study.
As reported in the original traffic study, US 15-501 provides intercity/intrastate access from the Town of Chapel Hill to I-40 and the City of Durham. Sage Road serves suburban residential and commercial developments and functions as a connector from US-15/501 to Erwin Road. Erwin Road is a minor northeast-southwest arterial that facilitates traffic from NC 751 in Durham to US 15-501 in Chapel Hill. Weaver Dairy Road is a minor arterial that connects to Martin Luther King, Jr. Boulevard west of the study area and serves numerous residential developments between MLK, Jr. Boulevard and Erwin Road. Old Sterling Drive and Eastowne Drive are collector streets that service residential and commercial developments to the south and east of the proposed project.
This report analyzes and presents the transportation impacts that the Chapel Hill Bible Church Park and Ride site will have on the following intersections in the project study area:
· Erwin Road and Sage Road
· Erwin Road and Weaver Dairy Road
· Sage Road and Old Sterling Drive
· Old Sterling Drive and Eastowne Drive
· Eastowne Drive/Lakeview Drive and US 15-501
· Old Sterling Drive and Bible Church Site Driveway/Existing Commercial Driveway
· Erwin Road and Bible Church Site Driveway/Covington Drive
The signalized intersection of Eastowne Drive/Lakeview Drive and US 15-501 and the unsignalized intersection of Eastowne Drive/Old Sterling Drive were added to the original study area to analyze the effects of site traffic using Eastowne Drive to access the proposed park-and-ride facility instead of using Sage Road to connect to Old Sterling Road. The Sage Road/Old Durham Road and US 15-501 intersection is not specifically analyzed in this report, since any potential impacts were analyzed in the original analysis and that represented a worst-case condition if site traffic chose that route to access the proposed site. The original report indicated that no mitigation was necessary for the US 15-501/Sage Road intersection due to site traffic impact.
As indicated in the original traffic impact study for the Bible Church Park-and-Ride Lot, site trips are rerouted peak-hour trips and some intersections may experience more delay with the left or right turn movements, though no new study area trips are assumed to be generated due to the facility. Some intersection movements may also experience LESS delay in the future build-out scenario due to rerouted trips.
Table ES-1A shows the estimated number of trips generated by the Bible Church Park and Ride during the AM and PM peak hours of adjacent streets. This data remains the same from the original traffic impact study.
Table ES-1A
Weekday Vehicle Trip Generation Summary
|
Scenario |
Development Density |
% Traffic Entering |
% Traffic Exiting |
TRIPS |
Trips Generated |
|
|
IN |
OUT |
|||||
|
Daily Traffic |
241 spaces |
50% |
50% |
241 |
241 |
482 |
|
AM Peak |
241 spaces |
100% |
0% |
241 |
0 |
241 |
|
PM Peak |
241 spaces |
0% |
100% |
0 |
241 |
241 |
CHT has proposed adding an additional 26 buses per day to service the park-and-ride lot. Nine buses with 20 minute headways are proposed between 6:00 am to 9:00 am and 3:00 pm to 6:00 pm. Table ES-1B summarizes the new CHT bus trips during the peak hours.
Table ES-1B
Weekday Vehicle Trip Generation Summary
|
Scenario |
Development Density |
% Traffic Entering |
% Traffic Exiting |
TRIPS |
Trips Generated |
|
|
IN |
OUT |
|||||
|
Daily Traffic |
26 buses |
100% |
100% |
26 |
26 |
52 |
|
AM Peak |
3 buses |
100% |
100% |
3 |
3 |
6 |
|
PM Peak |
3 buses |
100% |
100% |
3 |
3 |
6 |
The proposed route used by CHT buses is assumed to be similar to existing service in the study area – outbound buses will travel along US 15-501, turn left on Eastowne Drive to access Old Sterling Drive and continue on Old Sterling Drive to the Chapel Hill Bible Church. An existing bus stop adjacent to the proposed park-and-ride lot will be used by park-and-ride patrons. Buses will then turn left onto Sage Road and head back to US 15-501 inbound.
Background Traffic
Six Town of Chapel Hill approved background traffic generators from the original traffic impact study are located in the study area and are listed below:
Background traffic methodologies and trip generation/distribution/assignment were made using information contained in previous traffic impact studies and existing traffic patterns. An ambient traffic growth percentage of three percent per year was applied to existing study area traffic volumes, based on information from previous traffic impact studies in the area and information obtained from the Town of Chapel Hill.
Impact Analysis
Peak Hour Intersection Level of Service
One existing intersection (Erwin Road and Sage Road) currently operates at a deficient Level of Service (LOS) in both AM and PM peak hours. Additional ambient and approved background development traffic growth will cause the intersection of Erwin Road and Weaver Dairy Road to operate over capacity in both peak hours in 2008 and cause the site driveway intersection with Erwin Road to operate over capacity for the stop-controlled left-turn movements in the PM peak hour. With the redistribution of AM and PM peak hour site-generated trips adjusted to the projected 2008 background traffic volumes, the intersection of U.S 15-501 and Eastowne Drive/Lakeview Drive will experience operational deficiencies in the 2008 build-out scenario – under the assumption that ALL site-related traffic uses the Old Sterling Drive to Eastowne Drive route to access US 15-501. A summary of the traffic operations for each intersection, related to vehicular delays (intersection average as a whole if signalized, critical movement if stop-controlled) and the corresponding Level-of-Service (LOS) is shown in Table ES-2 below.
Table ES-2 LOS and Delay Summary
|
|||||||||
|
Intersections |
Time Period |
2006 Existing |
2008 No-Build |
2008 Build |
2008 Mitigated |
||||
|
LOS |
Delay |
LOS |
Delay |
LOS |
Delay |
LOS |
Delay |
||
|
Erwin Road and Weaver Dairy Road |
AM |
D |
36.8 |
E |
62.2 |
E |
63.8 |
N/A |
N/A |
|
PM |
D |
37.9 |
E |
75.1 |
E |
75.7 |
N/A |
N/A |
|
|
|
|
|
|
|
|
|
|
|
|
|
Erwin Road and Sage Road |
AM |
F |
135.0 |
B |
11.4 |
B |
12.2 |
N/A |
N/A |
|
PM |
F |
262.5 |
B |
16.9 |
B |
16.7 |
N/A |
N/A |
|
|
|
|
|
|
|
|
|
|
|
|
|
Sage Road and Old Sterling Drive / Coleridge Drive |
AM |
C |
15.4 |
C |
16.4 |
C |
16.4 |
N/A |
N/A |
|
PM |
C |
16.5 |
C |
18.7 |
C |
18.9 |
N/A |
N/A |
|
|
|
|
|
|
|
|
|
|
|
|
|
Old Sterling Drive and Bible Church Dr / Commercial Dr |
AM |
B |
11.2 |
B |
11.5 |
B |
12.3 |
N/A |
N/A |
|
PM |
B |
11.3 |
B |
11.6 |
B |
14.2 |
N/A |
N/A |
|
|
|
|
|
|
|
|
|
|
|
|
|
Erwin Road and Bible Church Dr / Covington Dr |
AM |
C |
24.7 |
D |
28.5 |
D |
32.9 |
N/A |
N/A |
|
PM |
E |
43.5 |
F |
58.7 |
F |
146.7 |
N/A |
N/A |
|
|
|
|
|
|
|
|
|
|
|
|
|
US 15-501 and Eastowne Drive/Lakeview Drive |
AM |
C |
22.8 |
C |
25.8 |
C |
26.2 |
C |
23.7 |
|
PM |
D |
37.6 |
D |
44.7 |
E |
57.2 |
D |
39.2 |
|
|
|
|
|
|
|
|
|
|
|
|
|
Eastowne Drive and Old Sterling Drive |
AM |
B |
11.7 |
B |
12.1 |
B |
13.4 |
N/A |
N/A |
|
PM |
B |
11.4 |
B |
11.7 |
C |
16.2 |
N/A |
N/A |
|
|
N/A – Not Applicable or No Improvements Necessary |
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As stated previously in this report, the redistribution of traffic volumes from routes that normally would serve traffic to and from the UNC campus (US 15-501/Erwin Road/Weaver Dairy Road) causes some intersection movements to operate better than they do in the 2008 No-Build Scenario, and thus delays for overall intersection operation may only marginally increase or possibly decrease. This is due to the removal of traffic volumes from congested/high volume lanes to lower volume turning lanes, for example.
Access Analysis Revisions
Access to the proposed site is assumed to remain the same from the original traffic impact study. The only change regarding site access is the assumption that site-related traffic to/from the US 15-501 corridor north and east of the Bible Church will use Eastowne Drive and Old Sterling Road to access the site, avoiding traffic congestion along US 15-501. The original study assumed that this portion of site traffic would use US 15-501 and Sage Road to access Old Sterling Drive and the site entrance/exit located along Old Sterling Drive.
Access issues and vehicle queuing estimates for the site driveway at Erwin Road remain unchanged from the original traffic impact study. Access at the Old Sterling Drive intersection with the existing site driveway will change as vehicles are routed westbound on Old Sterling Drive into the site and make a left-turn coming out of the site. The is adequate queue storage distance for traffic operations making the left-turn out of the site (over 100 feet of storage and separate left-turn and right-turn lanes currently provided).
Access for pedestrians and bicyclists is unchanged from the original traffic impact study.
Signal Warrant Analysis
As part of an NCDOT Spot Safety Project, a temporary traffic signal will be installed at the intersection of Erwin Road and Sage Road by the 2008 project completion year for the park-and-ride lot. As part of NCDOT Transportation Improvement Program (TIP) Project U-3306, the intersection of Erwin Road and Sage Road will be modified in 2009 when Weaver Dairy Road is realigned with this existing intersection. Based on projected traffic volumes, none of the other unsignalized intersections in the project study area would warrant the installation of a traffic signal based on the methodology found in the 2003 Manual on Uniform Traffic Control Devices (MUTCD). A warrant often satisfied from the MUTCD methodology is the Peak Hour Warrant, which would have comparable data collected from this study. Based on Figure 4C-4 from the MUTCD 2003, no study area intersection with the redistributed Bible Church park-and-ride site trips added would warrant the installation of a signal based on the Peak Hour thresholds.
Other Transportation-Related Analyses
Other transportation-related analyses relevant to the 2001 Town of Chapel Hill Guidelines for the Preparation of Traffic Impact Studies were completed as appropriate in the original traffic impact study. The following topics listed in Table ES-3 on the next page are germane to the scope of this additional analysis.
Table ES-3. Other Transportation-Related Analyses
|
Analysis |
Comment |
|
Generalized Peak Hour and/or Daily LOS Analysis |
Planning-level corridor LOS Analyses are not necessary for this study. Site traffic impacts are related to redistribution of traffic, and not the addition of traffic in the long or short-term.
|
|
Signal Phasing Analysis |
Signal phasing for existing/future conditions produces optimal traffic operations at the signalized intersections under study.
|
|
Progression Analysis |
The US 15-501 intersection signal at Eastowne Drive/Lakeview Drive is coordinated with the upstream/downstream signals on US 15-501 to provide optimal traffic progression on the corridor. If a signal is added at the Erwin Road/Sage Road intersection in the future, it would be beneficial to coordinate timing at this signal to the nearby Erwin Road/Weaver Dairy Road signal. Ultimately, coordination between these signals will not be needed once Weaver Dairy Road is realigned with Sage Road to form one intersection.
|
|
Turn Lane Storage Requirements |
No additional changes to any turn lane storage requirements were found in this study.
|
|
Appropriateness of Acceleration/ Deceleration Lanes |
Given the proposed configuration of site driveways, the lane geometrics, traffic patterns and posted speeds on Erwin Road and Sage Road, no special acceleration or deceleration lanes are required due to the proposed Park-and-Ride development.
|
|
Pedestrian and Bicycle Analysis |
Existing pedestrian access and connectivity is good through the study area. Besides short lengths of widened outside lanes on Sage Road and Erwin Road, no roadways with specific bicycle amenities exist in the study area.
|
|
Public Transportation Analysis |
Public transportation service to the site is excellent, with on-street bus stops immediately adjacent to the site and multiple routes serving the study area.
|
|
Sight Distance Analysis |
No changes in sight distance analysis were analyzed for this addendum to the original traffic impact study.
|
|
Accident Analysis |
No additional accident analyses were completed for this addendum to the original traffic study.
|
MITIGATION MEASURES / RECOMMENDATIONS
A.) Planned Improvements
The previously mentioned NCDOT Spot Safety Project is expected to signalize the intersection of Erwin Road and Sage Road in 2007. NCDOT TIP project U-3306 is expected to start construction in 2009 and realign Weaver Dairy Road to tie into the existing Erwin Road / Sage Road intersection. As part of this project, a permanent signal will be installed for the intersection, thus mitigating traffic operations problems along Erwin Road at its intersections with Weaver Dairy Road and Sage Road.
B.) Background Committed Improvements
No background improvements are committed by other study area background project developments that specifically affect study area intersections.
C.) Applicant Committed Improvements
Based on the concept plan provided, there are no transportation-related improvements to be made external to the site property. The concept plan provided shows that the development will delineate between church and park-and-ride parking spaces internal to the site. The internal circulation plan for vehicles is the same as the existing parking lot configuration, featuring two driveways on Erwin Road and one on Old Sterling Drive. Park-and-ride traffic will likely only use the driveway on Erwin Road, closest to the park-and-ride spaces. The two site driveway connections have a separate left-turn and right-turn lane exiting the site.
Since the UNC-CH employees will use the existing bus stop on Old Sterling Drive, no buses will be routed through the church parking lots or access driveways.
D.) Necessary Improvements
With the redistribution of all site-related traffic from US 15-501 through Eastowne Drive onto Old Sterling Drive, an external roadway improvement is potentially necessary to due to site traffic impacts. The intersection of Old Sterling Drive and Eastowne Drive is expected to operate acceptably during both peak hours with the addition of site-related park-and-ride traffic and CHT buses. The intersection of Eastowne Drive/Lakeview Drive and US 15-501 operates over capacity in the PM peak hour in the 2008 site build-out year, primarily due to a significant traffic volume increase for left-turns out of Eastowne Drive attributable to site traffic. The relative percentage of site traffic impact on this intersection is negligible in relation to overall peak hour traffic volumes on the US 15-501 corridor. However, a potential improvement recommended to improve operations of this intersection would be to restripe the Lakeview Drive intersection approach for a shared left-turn/through lane and an exclusive right-turn lane instead of its current configuration of an exclusive left-turn lane and through/right-turn lane. Since the highest proportion of traffic at this approach in both peak hours is right-turning vehicles, this restriping would allow more efficient operations for both Lakeview Drive and Eastowne Drive traffic during their traffic signal phase. The signal timing for this intersection should also be revised if this improvement is implemented to maximize the efficiency of the Eastowne Drive/Lakeview Drive signal phase.
Another potential improvement that would yield operational benefits for the Eastowne Drive left-turn approach would be to add a signal phase for protected-permitted left-turns for this movement, along with the restriping improvement for the Lakeview Drive approach.
CHT bus service impacts to study area intersection operations are negligible, since only three buses per peak hour (six total trips to and from site) are expected to affect the study area.
Even though the intersection of Erwin Road and Weaver Dairy Road operates at LOS E during the AM and PM peak hours for Condition 3, the upcoming NCDOT Spot Safety Project will signalize the intersection of Erwin Road and Sage Road and vastly improve traffic operations along Erwin Road in the vicinity of the two intersections by the 2008 build out year. At the intersection of Erwin Road and Bible Church Driveway, the left-turn and right-turn lanes are separated, so the right-turning vehicles are not delayed. Though left-turning vehicles may experience lengthy delay in the PM peak hour once the park-and-ride lot is fully operational the expected left-turn queue length is 140 feet, which can be contained within the site.
As stated in the original traffic impact study, the Applicant should provide additional signage on Erwin Road, Sage Road, and Old Sterling Drive to clearly delineate that the Bible Church Lot is a Park-and-Ride facility for vehicles with UNC Permits only.