Engineering Report: Shasta-Trinity National Forest. Shasta McCloud Management Unit. Analysis of. National Forest System Road 37N79

Transcription

1 Engineering Report: Shasta-Trinity National Forest Shasta McCloud Management Unit Analysis of National Forest System Road 37N79 (milepost 0.56 to 2.28) for Motorized Mixed Use Designation

2 Forest: Shasta-Trinity Road Number: 37N79 Management Unit: Shasta McCloud Road Name: Kosk Creek Time of Visit: Study Segment road data from the forest transportation atlas: Segment 1: End of pavement to private driveway Beginning Mile Post: 0.56 Ending Mile Post: 1.10 Segment 2: Private driveway to old slump (repaired) Beginning Mile Post: 1.10 Ending Mile Post: 1.48 Segment 3: Old slump (repaired) to guardrail barrier Beginning Mile Post: 1.48 Ending Mile Post: 2.15 Segment 4: Guardrail barrier to Kosk Creek Beginning Mile Post: 2.15 Ending Mile Post: 2.28 Traffic Service Level: A B C D Objective Maintenance Level: Operational Maintenance Level: Maintenance by: Forest Service (FS) Non-Forest Service ROW or jurisdiction? Yes No Any road use agreements, maintenance agreements, or other encumbrances? Yes No 2

3 Description of agreements or encumbrances: The southern portion of the road crosses through private property. As of 12/2011 the Forest transportation atlas documents Forest Service jurisdiction for the entire road, including all study segments. There are a number of private driveways and private access routes along the route from MP 0.0 to approximately MP 1.3 (see Figure 11 for the northernmost private driveway observed). Subject to Highway Safety Act? Yes No Non-highway-legal vehicles currently permitted? Yes No Would motorized mixed use be consistent with State and local laws? Yes No The proposed segment is 1.72 miles and therefore would be consistent with California Vehicle Code (CVC), Combined Use Highways Designation (CVC Division 16.5, Chapter 2, Article 1, Section 38026). Based on the CVC and Forest Service Region 5 guidelines, the designation of motorized mixed use requires California Highway Patrol notification prior to designation. Based on the response from the CHP commissioner, the Forest may reconsider the decision to designate MMU and/or may adjust mitigation measures needed for implementation. Description of road management objectives (RMOs), existing use, and proposed use: NFSR 37N79 has traditionally served administration of the STNF, including fuels and vegetation management, commodity extraction, fire suppression, and recreation. The road also provides access to private land, including residential properties as well as commercial timber land. The road is considered a highway by the Forest Service and is partially (segment 1) managed in accordance with the Highway Safety Act. The road is managed for passenger car vehicles and is appropriately posted with horizontal route identification markers. It is currently managed as open only to highway-legal vehicles. The road segment studied for this report is proposed to be managed for all motor vehicles, with motorized mixed use. The proposed use of non-highway-legal vehicles on highway segments would be restricted to licensed operators only, in accordance with State law. 3

4 General Considerations: All motor vehicle operators need to be cognizant of the applicable State laws, and how they pertain to each age group, vehicle type, and National Forest System road classification (see next bullet). Through authorities delegated by the Secretary, the Forest Service may restrict or control use to meet road management objectives (36 CFR 212.5). The STNF currently manages this road as a highway, in accordance with the Highway Safety Act. The road is therefore subject to the provisions of the California Vehicle Code (CVC) for highways. Operators on roads managed by the Forest Service for passenger cars (maintenance level 3-5) are required to be in possession of a valid state driver s license. State OHV Regulations: To operate on public lands, off of highways, motor vehicles must have either a street-legal license plate or a red sticker or a green sticker. For more information, see the CA State Parks Off-Highway Motor Vehicle Recreation site, California has: -requirements for ATV safety -conditions for operating ATVs -OHV equipment requirements -OHV operation requirements Summary of Findings: The road is maintained to a standard allowing efficient passenger car through traffic at speeds up to 25 mph on segment 1. Due to slide repairs and winding, rough conditions, segments 2-4 allow high clearance vehicle traffic with speeds up to 15 mph for reasonable and prudent drivers on straightaways. Segment 1 begins at the end of pavement and where a private driveway intersects the study segment. This location is not adequate as an OHV staging area. One potential staging area could be the dispersed camping site adjacent to Kosk Creek (approximate milepost 1.8). Designating the road segment for motorized mixed use, with mitigation, results in a risk assessment of low crash probability and moderate crash severity. Road hazard mitigation should be prioritized regardless of mixed use, along with 4

5 implementing a comprehensive communication, management, and enforcement plan. Associated implementation costs will depend on the designated allowed use. Implementing mitigation measures will reduce crash probability. Segment 1 appeared in accordance with the Forest transportation atlas assigned operational maintenance level of 3. Segments 2 and 3 were observed as operational maintenance level 2. Segment 4 is behind a guardrail barrier; this road is closed and therefore being managed as operational maintenance level 1. Segment 4 is not drivable beyond the Kosk Creek crossing at milepost 2.28 (bridge removed). Factors Considered: 1. Operator considerations: The current use on NFSR 37N79 segment 1 appears to be consistent with State law and Forest Service policy for operational maintenance level 3 roads. The current use on NFSR 37N79 segments 2-3 appears to be consistent with State law and Forest Service policy for operational maintenance level 2 roads. The current use on NFSR 37N79 segment 4 appears in accordance with Forest Service policy for operational maintenance level 1 roads only non-motorized uses allowed. Private, residential, commercial, recreational and administrative traffic can be expected along this segment. 2. Crash history: None provided by unit 5

6 3. Observed Traffic volume and type: Non-highway-legal vehicles: < 12 inch tread width < 50 inch tread width >50 inch tread width Highway-legal vehicles: < 12 inch tread width < 50 inch tread width >50 inch tread width Passenger cars Commercial vehicles Recreation vehicles (RV s) None observed 4. Speed - Anticipated average speed (85 th percentile): The road segment was driven at various speeds to simulate conditions encountered by a reasonable and prudent driver in a passenger car. Based on observation and engineering judgment, speeds are anticipated as: 25 mph straightaways on segment 1 15 mph straightaways on segments Road surface type: Segment 1 is surfaced with aggregate. Segments 2-4 are mostly native surfaced. The traveled way width is variable; all segments are considered single-lane. Segment 1 is well maintained and suitable for passenger cars. Segments 2-3 have multiple portions with rutting and where old slides and slumps were repaired; high clearance vehicles are recommended for these segments. There are occasional turnouts available through the study segments. They are not intervisible. Segment 4 is behind a vehicle barrier and has a naturally deteriorating travelled way with grass growing in the roadbed. 6. Intersections with other roads and trails: The sight distances at the managed intersections are rated fair to good. The intersections could be improved with vegetation clearing and improved signing. There are no non-sign traffic strategies (i.e., entrance treatment) on this road. 6

7 7. Other roadway factors: There is a Road Closed Miles Ahead, Local Traffic Only sign at the Baker Creek Road intersection. This is likely from the Kosk Creek Bridge removal or when the roadway was closed at the slide between segments 2 and 3 (since re-opened). The bridge over Kosk Creek (end of segment 4) has been removed. There is a deeply rutted (3-foot depth) ramp that accesses Kosk Creek at this point, but it does not appear drivable nor suitable for motor vehicles. No evidence of motor vehicle use was observed from segment 4 to the portions of NFSR 37N79 along the west side of the creek. There was evidence of equestrian use on segment 4 as well as at the Kosk Creek crossing. 8. Roadside conditions: Segments 2-4 have encroaching brush into the travelled way, in particular at Baker and Shotgun Creek crossings. Roadside slopes are generally gentle to moderate; however, just south of Baker Ck there is one short segment of steep fill slopes dropping to Kosk Creek. Baker Creek and Shotgun Creek have improved multi-plate culverts installed that appear to be sized for 100-year flood events (see Figure 22). These crossings have narrow travelled ways and deep through-fills. 9. Risk without mitigation if designating the road segment open to all motor vehicles : Segment 1: Crash probability: High Med Low Crash severity: High Med Low Segments 2-4: Crash probability: High Med Low Crash severity: High Med Low 7

8 Crash probability was assessed based factors including: Traffic volume, rates of speed, alignment, road segment uses, sight distance, traveled way surface and width, operator requirements. Crash severity was assessed based on: Roadway geometry (embankments, slopes, horizontal and vertical alignments), difference in vehicle sizes, difference in speeds of OHVs and full-size passenger vehicles, potential path and objects encountered if a vehicle left the traveled way. Alternatives and Mitigation Measures: Alternatives and mitigation measures are presented to assist with safe road management. They are to be considered, should the agency have the appropriate time, workload, and funding based on competing priorities. For all situations, the following mitigation measures apply: Clear communication and education to the visitors on allowed uses, safe motor vehicle use, and natural resources (informational signing and kiosks, maps, website, etc.). Improved route identification signing, consistent with the forest visitor map and forest motor vehicle use map. Repair and replace devices as needed. Clear brush and trees, especially along curves and at intersections, to improve sight distance. warning: improved sight distance may result in higher speeds Removal of roadside hazards such as boulders, trees, and debris. Implement and maintain the appropriate Forest Service traffic management strategies for the assigned operational maintenance level. Combine the appropriate enforcement measures with the allowed uses for the road. Coordinate with other agencies to improve enforcement consistency. Utilize a monitoring program to better determine the appropriate management strategy for the types of use, new technologies, changes in visitor demands, and resource protection measures. In addition, these mitigation measures would apply to the following alternatives. Although the following alternatives are not comprehensive for the situation, they represent the most likely and/or practical options based on engineering judgment. Alternative 1: Designate the road segments as open to highway-legal vehicles only. Continue to manage the road in accordance with maintenance level 3 standards. Maintain all roadway signing to MUTCD standards. Approximate Implementation Cost: $ 0 Expected risk: Crash probability: High Med Low 8

9 Crash severity: High Med Low * This results in a non-motorized mixed use situation. This option carries forward the existing Road Management Objectives. However, since the conditions on segments 2-4 are currently at maintenance level 2 and 1 standards, these road segments should eventually be improved in accordance with ML3 standards. Alternative 2: Designate the road segments as open to all motor vehicles, including highway legal and non-highway-legal vehicles. Maintain the road in accordance with maintenance level 3 standards. Improve education and enforcement communication to explain the complexities of various allowed uses on the road. Install appropriate warning signs ( Share the Road ) of a type approved by the Department of Transportation on and along the highway to identify and communicate the potential hazards related to motorized mixed use. Improve sight distance by clearing vegetation along shoulders, curves, and at intersections. Implement appropriate traffic management strategies on intersecting maintenance level 2 roads. Notify the Commissioner of the California Highway Patrol and review their opinion. Approximate Implementation Cost: $ 5000 Covers safety signing, roadside brushing, guardrail barrier removal, and surface blading to provide for passenger car vehicles. Expected risk: Crash probability: High Med Low Crash severity: High Med Low Alternative 3: Designate the road segments as open to all motor vehicles, including highway-legal and non-highway-legal vehicles. Downgrade the road in accordance with maintenance level 2 standards. This would require implementing the appropriate traffic management strategies, in this case either discourage passenger car vehicles and/or accept -or- encourage high clearance vehicle traffic. This option is not consistent with the assigned road objective maintenance level. Consider removing features such as ditches & culverts which may require frequent maintenance more associated with ML 3-5 roads. Consider long-term impacts to the rest of the road not included in the 9

10 altered segment. Approximate Implementation Cost: $ 6,000 per mile. This would only be required for segment 1 and for removal of the guardrail barrier. Segments 2-4 are already at the ML2 standard. Expected risk: Crash probability: High Med Low Crash severity: High Med Low Alternative 4: Separate use in accordance with the varying existing road conditions. Change segments 2-3 to operational maintenance level 2 and allow all motor vehicles to use these segments. Approximate Implementation Cost: $ 500 (covers appropriate signing to inform of the change in allowed uses along the route). Expected risk: Crash probability: High Med Low Crash severity: High Med Low Eventually, this alternative may also want to include: utilization of the dispersed camping site along Kosk Creek in segment 3 as a staging area for OHVs opening segment 4 with removal of the guardrail barrier and also improvement and stabilization of the Kosk Creek crossing (if motor vehicle access is desired on the west side of the creek) appropriate travel management strategies physically implemented at Arvison Flat and beyond to properly manage designated uses Alternative 5: Construct OHV trail segment(s) to allow non-highway-legal vehicles to bypass the road and access adjacent maintenance level 2 roads. The terrain in this area is moderate to steep and would not readily provide for a parallel trail system. Approximate construction cost: $15000 per mile * Alternative costs do not include planning, agreements, and long term maintenance costs associated with a new NFS trail. Crash probability: High Med Low Crash severity: High Med Low * This results in a non-motorized mixed use situation. 10

11 Final Comments: Signing on National Forest System roads will conform to the standards presented in the FS sign and poster guidelines In addition, roads managed under the Highway Safety Act, including the study segment here, must comply with the standards in the MUTCD According to the Sign and Poster Guidelines for the Forest Service (2005): The following priorities are to be used to minimize the potential conflicts of mixed use: o Provide separate facilities. o Separate use periods. Roads may be designated for separate use periods such as season, weekday/weekend, or day/night. Notify the public of the locations, effective dates, times, and duration that the roads may or may not be used. Provide appropriate signs as shown in Chapter 3A. o Manage concurrent use. Upon designation and prior to allowing any mixed use, the Forest Supervisor is responsible for appropriately signing and mapping the route such that the dual traffic use is clear to all users. 11

12 Photos & Map Figure 1: Looking south from beginning of study segment 1; milepost

13 Figure 2: Beginning of study segment 1 (left) at end of pavement; private driveway to right. Figure 3: Sierra Pacific Industries access road intersection, segment 1. 13

14 Figure 4: End of straightaway, segment 1. Figure 5: Looking north at the intersection with Baker Creek Road (right), a residential access route; segment 1, milepost

15 Figure 6: Looking north along a straightaway in segment 1; steep fill slope on left drops to Kosk Creek. Figure 7: Looking north at the end of segment 1; private driveway and bridge to left, NFSR 37N79 segment 2 veering to right, milepost

16 Figure 8: South portion of segment 2, looking north. Figure 9: Narrow road at previous slope failure, signed with warning signs and object markers. 16

17 Figure 10: Segment 2 roadway looking north. Figure 11: Segment 2, looking north at intersection with private driveway (right); milepost

18 Figure 12: Milepost 1.48, old cut slope failure since repaired and opened. Figure 13: Intersection of Kosk Creek dispersed camping access (left) and segment 3 (right). 18

19 Figure 14: Dispersed camping site. Figure 15: Segment 3 straightaway, looking south. 19

20 Figure 16: Looking north at intersection of NFSR 37N79E (right) and segment 3 (left); milepost Figure 17: Guardrail barrier closure at milepost 2.15; segment 3 ends at barrier and segment 4 continues beyond. 20

21 Figure 18: Segment 4 looking north. Figure 19: Old Kosk Creek crossing, section 4, milepost Bridge no longer exists, steep ramp access creek to right of barrier. 21

22 Figure 20: Old bridge approach, east side of Kosk Creek, segment 4. 22

23 Figure 21: Ramp from old bridge approach down to Kosk Creek; rut is approximately 3 feet deep. 23

24 Figure 22: Multiplate culvert at Shotgun Creek; milepost

25 Study termini Figure 23: Forest Visitor Map zoom view with study road (mis-identified as 37N97). Prepared by: Chris Bielecki Logging Engineer, USDA Forest Service 25