2016-01-15_Illumination_Memo.pdf

2100 Southwest River Parkway Portland Oregon 97201 Telephone: 503.223.6663 Facsimile: 503.223.2701

DATE: January 15, 2016

TO: Kirk Loftsgaarden, Project Manager

Western Federal Lands Federal Highway Administration

FROM: Cameron Grile, PE, PTOE

SUBJECT: Tunnel Lighting Recommendations

PROJECT: WA NPS OLYM 2015(4), Spruce Railroad Trail Segment C

FHWA0000-0230

CC: John Maloney, DEA; File

INTRODUCTION

The Federal Highway Administration (FHWA), National Park Service (NPS), and Clallam County, Washington have partnered on the Spruce Railroad Trail project that is located on Lake Crescent near Port Angeles, Washington. The project converts an existing gravel/dirt hiking trail into a 10-12’ wide multi-use trail. The project has been split into four segments, A, B, C, and D. Segments A and B have not been designed yet, and

Segment D has been constructed. FHWA has contracted with David Evans and Associates, Inc. to provide technical support for the preliminary design (50%) of Segment C. This scope also includes the Lyre River parking area, approximately 2500 feet of trail alignment construction, the McFee Tunnel (Long Tunnel) rehabilitation, and the West Tunnel (Short Tunnel) rehabilitation. Part of the preliminary design requires a recommendation on the need for illumination in the two tunnels, which is the subject of this memo. Included in this memorandum is a summary of applicable standards, site conditions, and recommendations.

APPLICABLE STANDARDS

The project is following the design guidelines in the AASHTO Guide for the Development of Bicycle Facilities, 2012, 4th Edition. Section 5.2.12 of the guide includes a general statement “lighting should be provided in pathway tunnels” and “Daytime lighting of tunnels and underpasses is often needed.” The guide recommends pathway tunnel lighting to be designed in a manner similar to the design of roadway tunnels.

The Illuminating Engineering Society (IES) publishes RP-22-11, which provides a standard of practice for illuminating roadway tunnels. The RP-22-11 states that structures less than 80 feet in length do not require supplemental daytime lighting.

SITE CONDITIONS

The trail is part of the Olympic Discovery Trail (ODT) system and begins at the East Beach trailhead and follows the north shoreline of Lake Crescent for approximately 4 miles. The trail is surrounded by a steep slope and forest on one side and a narrow line of trees between the trail and the lake on the other side. The two tunnels on the project are within the first three miles of the trail. The McFee Tunnel is approximately 390 feet in length and is oriented in the northeast/southwest direction. The tunnel has a horizontal curve in the alignment and the

DATE: January 15, 2016 FROM: Cameron Grile, PE, PTOE

TO: Kirk Loftsgaarden, Project Manager SUBJECT: Tunnel Lighting Recommendations opposite exit would not be visible from the entrance. The West Tunnel is approximately 140 feet in length and generally runs east/west with little curvature in the alignment. The tunnels are old railroad tunnels and are very large in size and a considerable amount of light does enter the tunnels.

RECOMMENDATIONS

Based on the AASHTO design guide, the length of both tunnels and the site conditions, lighting should be provided or mitigated for. Lighting the tunnels will improve safety and security as well as help trail users eyes adjust to the change from natural (outdoor) lighting to very dark light conditions (if not illuminated).

Lighting Considerations

Because of the location of the tunnels, providing lighting may not be practical. Powering the light fixtures would require running power from the nearest power source or installing a solar power option that could be costly.

Maintenance and vandalism should also be considered. The rural location of the tunnels could lend itself to a higher rate of broken fixtures and longer durations in which lighting is not operational. The inclusion of a protective cage could help deter vandalism. Tunnel moisture and climate may affect long term maintenance of the fixtures. Accessibility to the fixtures would require lower mounting heights and/or a small maintenance vehicle to enter the tunnels.

Lighting Mitigation

In the event that tunnel lighting is not provided, the following options could be included in the project to assist safe secure passage through the tunnel:

Post ODT trail user rules to raise awareness of proper trail courtesy, see adjacent figure.

Install reflectors within the tunnels

Install additional signage alerting trail users to use reflective devices and lights during the day.

Require bicyclists to walk bikes through the tunnels.

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