Table 8 – Trip Distribution Assumptions
Route Percent Daily Trips AM Trips PM Trips
Soscol Ave (South) 45% 375 18 30
Soscol Ave (North) 35% 292 14 23
First St (West of Soscol Ave) 10% 83 4 7
First St (East of McKinstry St) 10% 83 4 7
TOTAL 100% 833* 40 67*
Note: * Trips may not add up to the calculated trip generation due to rounding Comparison to the Downtown Napa Specific Plan
Per the City’s 2012 Downtown Napa Specific Plan (DNSP), the project is located in the Oxbow area zoned “Tourist Commercial” (CT), which allows uses oriented towards tourists and other visitors to the community. The corresponding General Plan category is “Mixed Use,” which could include retail and office uses. The City has noted that there has been a shift from the mixed uses assumed in the DNSP from the currently proposed uses, which are predominantly hotels. As requested by City Staff, the anticipated trip generation for the proposed project was compared to the potential trip generation for retail and office uses to determine the equivalent amount of office and retail that would generate the same number of trips as the proposed project. The anticipated trip generation for these uses was estimated using standard rates published by the Institute of Transportation Engineers (ITE) in Trip Generation Manual , 10th Edition, 2017 for “General Office Building” (Land Use #710) and “Shopping Center” (Land Use #820). The results are summarized in Table 9.
Table 9 – Trip Generation Comparison
Land Use Units Daily AM Peak Hour PM Peak Hour
Rate Trips Rate Trips In Out Rate Trips In Out
Proposed Project 834 40 24 16 66 34 32
Shopping Center 17.4 ks f 37.75 657 0.94 16 10 6 3.81 66 32 34 Office 57 ksf 9.74 555 1.16 66 57 9 1.15 66 10 56
Note: ksf = 1,000 sf
The amount of retail and office uses that would generate an equivalent number of p.m. peak hour trips as the proposed project would include 17,400 square feet of retail and 57,000 square feet of office uses. Under its current zoning, the site could generate higher volumes with other permitted uses compared to what is projected for the proposed project. In comparing the proposed hotel use to shopping center uses, these would have similar directionality in traffic during the more critical p.m. peak hour. However, in comparison to office uses, there would be more traffic leaving the site during the p.m. peak hour generated by the office use. Therefore, the project has similar or less directionality impacts compared with other allowable uses in the Specific Plan Area.
Crucial Corridor Analysis
Per the City’s General Plan, the City of Napa has established a circulation policy in its traffic management strategy that reserves traffic capacity within major corridors for community-wide circulation. These corridors are known as “crucial corridors” and City policy has limited development with direct access to these streets to low traffic- ATTACHMENT 13
18 Traffic Impact Study for the First and Oxbow Hotel
April 23, 2019
generating uses. Per the City of Napa Policy Guidelines for Traffic Impact Analysis for Private Developmental Review , uses along crucial corridors shall generate less than 520 daily trips per gross acre.
The proposed western building would front Soscol Avenue which is a designated crucial corridor and is therefore required to meet the City’s crucial corridor requirements. This portion of the project is expected to generate 380 daily trips as shown in Table 10.
Table 10 – Daily Trip Generation for the Proposed Western Building Land Use Units Daily
Rate Trips
Hotel 37 rooms 8.36 309
Shopping Center 1.873 ks f 3 7.75 71
Total 380
Note: ksf = 1,000 s f
Per the site plan, the proposed western building would have a gross square footage of 60,307 square feet, which translates to approximately 1.38 acres. The building is anticipated to generate approximately 275 daily trips per acre; therefore, the project meets the City’s crucial corridor requirement.
Intersection Operation
Existing plus Project Conditions
Upon the addition of project-related traffic to the Existing volumes, the study intersections would be expected to continue operating acceptably at the same levels of service during both peak hours. Project traffic volumes are shown in Figure 6, and the resulting levels of service are summarized in Table 11.
Table 11 – Existing and Existing plus Project Peak Hour Intersection Levels of Service Study Intersection
Approach
Existing Conditions Existing plus Project
AM Peak PM Peak AM Peak PM Peak
Delay LOS Delay LOS Delay LOS Delay LOS
1. Soscol Ave/McKinstry St 5.9 A 6.3 A 6.2 A 6.9 A
2. Soscol Ave/First St 38.3 D 36.7 D 38.1 D 36.6 D
3. McKinstry St/First St 1.9 A 1.9 A 2.3 A 2.5 A
Northbound (McKinstry St) Approach 12.3 B 14.9 B 12.6 B 16.5 C Southbound (McKinstry St) Approach 11.1 B 13.0 B 11.6 B 14.0 B Notes: Delay is measured in average seconds per vehicle; LOS = Level of Service; Delay for stop-controlled approaches is shown in italics
It should be noted that with the addition of project-related traffic volumes, average delay at the intersection of Soscol Avenue/First Street decreases during both peak hours. While this is counter-intuitive, this condition occurs when a project adds trips to movements that are currently underutilized or have delays that are below the intersection average, resulting in a better balance between approaches and lower overall average delay.
Finding – The study intersections would be expected to continue operating acceptably with imperceptible changes in average delay upon the addition of project-related traffic to Existing volumes. ATTACHMENT 13
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Tra c Impact Study for the First and Oxbow Hotel
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Figure 6 – Project Tra c Volumes
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20 Traffic Impact Study for the First and Oxbow Hotel
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Existing plus Approved plus Project Conditions
Upon the addition of project-generated traffic to the anticipated Existing plus Approved volumes, the study intersections are expected to continue operating acceptably during both peak hours. The Existing plus Approved plus Project operating conditions are summarized in Table 12.
Table 12 – Existing + Approved and Existing + Approved + Project Peak Hour Intersection Levels of Service Study Intersection
Approach
Existing plus Approved
Conditions
Existing plus Approved plus
Project Conditions
AM Peak PM Peak AM Peak PM Peak
Delay LOS Delay LOS Delay LOS Delay LOS
1. Soscol Ave/McKinstry St 6.4 A 8.2 A 6.7 A 8.6 A
2. Soscol Ave/First St 37.3 D 36.0 D 37.2 D 35.9 D
3. McKinstry St/First St 2.7 A 3.8 A 3.1 A 4.7 A
Northbound (McKinstry St) Approach 14.9 B 24.1 C 15.4 C 28.2 D Southbound (McKinstry St) Approach 12.2 B 17.1 C 12. 7 B 19.5 C Notes: Delay is measured in average seconds per vehicle; LOS = Level of Service; Delay for stop-controlled approaches is shown in italics
Finding – Upon the addition of project-generated traffic to the anticipated Existing plus Approved volumes, the study intersections would be expected to continue operating acceptably, again, with imperceptible changes in average delay.
Future plus Project Conditions
Upon the addition of project-generated traffic to the anticipated Future volumes, the study intersections would be expected to continue operating at acceptable service levels during both peak periods. The Future plus Project operating conditions are summarized in Table 13.
Table 13 – Future+ Approved and Future + Approved + Project Peak Hour Intersection Levels of Service Study Intersection
Approach
Future plus Approved
Conditions
Future plus Approved plus
Project Conditions
AM Peak PM Peak AM Peak PM Peak
Delay LOS Delay LOS Delay LOS Delay LOS
1. Soscol Ave/McKinstry St 6.8 A 9.3 A 7.1 A 10.0 B
2. Soscol Ave/First St 38.1 D 37.3 D 38.0 D 37.2 D
3. McKinstry St/First St 2.1 A 2.2 A 2.5 A 2.9 A
Northbound (McKinstry St) Approach 14.2 B 18.5 C 1 4.8 B 20. 9 C Southbound (McKinstry St) Approach 12.6 B 15.6 C 13.3 B 17.2 C Notes: Delay is measured in average seconds per vehicle; LOS = Level of Service; Delay for stop-controlled approaches is shown in italics
Finding – Upon the addition of project-generated traffic to the anticipated Future volumes, the study intersections would be expected to continue operating acceptably with imperceptible changes in average delay.
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21 Traffic Impact Study for the First and Oxbow Hotel
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Alternative Modes
Pedestrian Facilities
The existing sidewalks on First Street along the project frontage would adequately serve the project, effectively connecting the site to the surrounding pedestrian network. In general, the pedestrian network surrounding the project site is well connected and provides adequate access for pedestrians, especially between Downtown Napa and the Oxbow Market area. ADA accessible ramps are also provided on the existing sidewalk at the railroad crossing area.
Finding – Pedestrian facilities serving the project site are adequate.
Bicycle Facilities
Existing bicycle facilities, including bike lanes on Soscol Avenue, together with the planned bike lanes on First Street outlined in the City of Napa Bicycle Plan would provide adequate access for bicyclists and effectively link the project site to the surrounding bicycle network. Regarding the project frontage on First Street and plans for bike lanes, it is noted that the existing parallel parking on the south side of First Street would be removed and a Class II bike lane would be installed as part of the bike lane project.
Finding – Off-site bicycle facilities serving the project site are adequate.
Bicycle Storage
The City requires nonresidential projects with more than ten vehicle parking spaces to provide a minimum of two bicycle storage spaces with one additional space for every 10 vehicle spaces in excess of 20. With a planned supply of 124 vehicle parking spaces, the proposed project would need to provide at least thirteen bicycle parking spaces to meet this requirement.
Recommendation – The project should provide at least thirteen bicycle parking spaces on-site.
Transit
Existing transit routes are adequate to accommodate project-generated transit trips. The existing stop on Soscol Avenue at 3rd Street is within acceptable walking distance of the site. Should a project patron or employee need to use a transit route not offered at this bus stop, it would be possible to walk to the Soscol Transit Center.
Additionally, the Wine Train depot is located within walking distance of the site and provides an opportunity for hotel guests to take advantage of this local attraction without using a vehicle.
Finding – Transit facilities serving the project site are adequate for the anticipated demand.
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22 Traffic Impact Study for the First and Oxbow Hotel
April 23, 2019
Access and Circulation
Site Access
Access to the site is proposed via two driveways. One is located on the south side of First Street west of the railroad tracks and the other is located on the north side of Water Street, just east of the railroad tracks.
The western building would be served by a single two-way drive aisle that would connect the First Street driveway to an underground parking garage. This driveway would be restricted to right turn movements in and out. The eastern building would be served by the full access driveway on Water Street, which would provide access to another below-grade parking garage.
Valet Operations
Valet parking services would be provided in front of the eastern building only, where all patrons would arrive for check-in. The sub-grade parking in the western building would be accessed by the valet drivers only. All existing parallel parking spaces along First Street would be removed as part of the plans to install bike lanes, and the curb set back to create the passenger loading area and valet space. This set-back area will include the majority of the east building frontage and is proposed to be at least 100 feet in length, with sufficient space to accommodate four to five vehicles. All employees would valet their own vehicles.
Water Street
Water Street would be converted from a public to a private street with a reduced cross-section as a result of the proposed project. The footprint of the hotel building would extend 20 feet into the 60-foot wide Water Street right-of-way. The project site plan depicts the reduced cross-section and shows an 11-foot travel lane in each direction with eight feet of parking and a ten-foot sidewalk on the south side of Water Street. Per section 170.06.030 of the City’s Municipal Code, private streets are not typically dedicated or maintained as public streets, they afford principal means of access to uses on two or more lots, and they should be approved by the City. Based on Section 16.36.030. Circulation and Traffic, the applicant should provide a feasible method for maintenance of, and parking enforcement on, Water Street upon conversion to a private street, which shall be subject to approval by the City.
Recommendation – Given that Water Street would be converted to a private street and modified to have a narrower cross section as a result of the proposed project, the applicant should provide a street maintenance and parking enforcement plan for City review.
Sight Distance
At driveways a substantially clear line of sight should be maintained between the driver of a vehicle waiting on the driveway and the driver of an approaching vehicle. Adequate time must be provided for the waiting vehicle to either cross the street, turn left, or turn right, without requiring the through traffic to radically alter their speed.
Sight distance should be measured from a 3.5-foot height at the location of the driver on the minor road to a 4.25- foot object height in the center of the approaching lane of the major road. Set-back for the driver on the crossroad is recommended as a minimum of 15 feet, measured from the edge of the traveled way.
Sight distances along First Street from the western project driveway were evaluated based on sight distance criteria contained in the Highway Design Manual published by Caltrans. The recommended sight distance for driveways is based on stopping sight distance, with approach travel speed used as the basis for determining the recommended sight distance.
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For the posted 25-mph speed limit on First Street, the recommended sight distance is 150 feet. Field measurements indicate that there is at least 150 feet of sight distance available to the west, which allows drivers to view traffic in the intersection with Soscol Avenue, and more than 250 feet of sight distance to the east along First Street. The latter sight distance condition assumes that vehicles are parked along the southern side of First Street, east of the railroad tracks.
The eastern driveway was not evaluated for sight distance since it is located at the end of a “dead end” street and vehicles would be exclusively entering from and exiting to the east.
Finding – Sight distance at the project driveway on First Street would be adequate for the posted speed limit.
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24 Traffic Impact Study for the First and Oxbow Hotel
April 23, 2019
Conclusions and Recommendations
Conclusions
· The proposed project is anticipated to generate an average of 834 daily trips, including 40 trips during the a.m. peak hour and 66 trips during the p.m. peak hour.
· The study intersections of Soscol Avenue/McKinstry Street, Soscol Avenue/First Street, and McKinstry Street/First Street are currently operating acceptably at LOS A, D, and A (respectively) during both peak hours.
Upon the addition of project-related traffic to the Existing volumes, the study intersection would be expected to continue operating at the same level of service during both peak hours. · Upon the addition of traffic associated with approved projects in the surrounding vicinity, the study intersections are expected to continue operating acceptably at LOS A, D, and A during both peak hours without and with project-generated traffic added.
· The project would meet the City’s crucial corridor requirements. · Existing and planned pedestrian, bicycle, and transit facilities would provide adequate access for the anticipated demand. No bicycle parking facilities are shown on the plans; however, the project needs to provide thirteen bicycle parking spaces on-site to meet City requirements. · Sight distance on First Street at the project driveway is adequate for the posted 25-mph speed limit. · On-site circulation is expected to operate acceptably.
Recommendations
· The project should provide at least thirteen bicycle parking spaces on-site. · The applicant should provide a street maintenance and parking enforcement plan for Water Street.
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25 Traffic Impact Study for the First and Oxbow Hotel
April 23, 2019
Study Participants and References
Study Participants
Principal in Charge Steve Weinberger, PE, PTOE
Assistant Engineer Kevin Rangel, EIT
Graphics/Editing/Formatting Katia Wolfe
Quality Control Dalene J. Whitlock, PE, PTOE
References
2013 Collision Data on California State Highways, California Department of Transportation, 2016 City of Napa Bicycle Plan, W-Trans, 2012
City of Napa Downtown Napa Specific Plan, MIG, 2012
City of Napa Policy Guidelines: Traffic Impact Analysis for Private Developmental Review, City of Napa, 2002 City of Napa Traffic Impact Study Guidelines, City of Napa, 2004 Downtown Napa Specific Plan, MIG, 2012
Envision Napa 2020: City of Napa General Plan, City of Napa, 2011 Highway Capacity Manual, Transportation Research Board, 2010 Highway Design Manual, 6th Edition, California Department of Transportation, 2017 Napa Valley Wine Train, http://winetrain.com
Statewide Integrated Traffic Records System (SWITRS), California Highway Patrol, 2012-2016 Traffic Analysis for Archer Napa Hotel Project, Kimley-Horn and Associates, 2014 Trip Generation Manual, 10th Edition, Institute of Transportation Engineers, 2017 VINE Transit, http://www.ridethevine.com
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ATTACHMENT 13
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Traffic Impact Study for the First and Oxbow Hotel
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Appendix A
Collision Rate Calculations