A Level of Service “improvement” project for Scotts Valley, CA

I live in a small town of 12,000 people in the Santa Cruz Mountains which received funding to rework a major intersection in town. The final design misses several opportunities to improve the intersection for those traveling on foot and on bike.

Scotts Valley: Mt Hermon / Scotts Valley Drive / Whispering Pines "Operational Improvement" plan

A note about directions: Mt Hermon at this intersection is aligned more north-south, and Scotts Valley more east-west, and the engineering documents refer to them that way. I think of Mt Hermon overall, however, as a east-west road, and Scotts Valley Drive as a north-south road, and the drawing has been slightly rotate to reflect this, so those are the directions I will use. I hope this isn’t too confusing.


The public input process took place in 2008, when I was new to town. I’m fairly certain I wouldn’t have known back then how to critique this project. I do now, though, so let’s use this as a case study so you, too, can know what to look for.

The above drawing shows the new design. The east-west road is Mt Hermon Road, a 35 MPH arterial which carries 33,000 vehicles per day (VPD); north-south Scotts Valley Drive handles 17,000 VPD. Mt Hermon has the green light signal priority, with demand actuation for Scotts Valley Drive and Whispering Pines. The major changes for this “operational improvement” at this intersection are replacing a long right-turn lane so it becomes a third westbound through lane on Mt Hermon, and extending the queue length of the westbound left turn lane from Mt Hermon to Whispering Pines.

Other changes include reducing the size of the pedestrian islands, adding “RRFBs” (pedestrian flashing signals), green paint for the existing bike lanes, and advance stop line “bike boxes” to the left turn lanes. I believe these will be the first such bike boxes in Santa Cruz County, for whatever that’s worth.


Let’s look at this design to see what you, too, should look for.

  • Transportation forecasting: Active transportation advocates often criticize the inaccurate modeling and assumptions used in transportation forecasting, and this project is a perfect example of forecasting failure. Road engineering firms make money doing the design work after the initial study, so of course they’ll tell you that you need more roadway capacity, duh.

    The 2008 traffic study for this intersection predicted a Level of Service (LOS) “F” at this intersection by 2015. This means people in cars could expect a delay of 80 seconds or more, and might even have to wait through more than a single red light cycle to pass the intersection. As of this year (2016), we experience a LOS “D” (35 to 55 second delay) for about two hours of the day, and LOS “A” (under 10 seconds delay) or “B” for most of the rest of the day.

  • Reduced air pollution! Among the listed project benefits are “reduction in air pollution and a lowering of fuel consumption thus, improving air quality” due to reduced delay by motorists at this intersection. This project design predates the SB 743 mandate to evaluate projects on their vehicle-miles-traveled impact, but even in 2008 we knew you improve air quality by reducing the total number of miles traveled, not by whisking even more cars through town. Think about it: 33,000 vehicles per day in a town of 12,000 people, and the city wants to make it even easier and faster to make more trips?
  • Safety improvements! The state funding application includes the question “Does this project increase safety?” The city engineer’s answer is a tautology — this project will improve safety because it improves safety! The common assertion that the projected delay inevitably leads to “driver frustration,” “potential conflicts” and, by implication, road rage, is such a cop out.

    The improvements proposed in this application are necessary to improve traffic flow and to address safety concerns. Without these improvements, traffic flow, driver frustration, congestion, and potential conflicts between motorists, pedestrians, bicyclists crossing the intersection are projected to worsen. These improvements are considered critical to provide a safe environment for motorists, bicyclists and pedestrians, school children and others in this heavily concentrated area of town.

  • Pedestrian improvements: This project will reduce the size of those already-tiny pedestrian refuge “porkchop” islands, while adding pedestrian beacons. This is the most dangerous intersection for pedestrians in Scotts Valley, and this intersection has a high volume of pedestrian traffic in spite of the hostile environment. Sight lines from Scotts Valley Drive to westbound Mt Hermon in particular are horrible for both pedestrians and drivers. The flashing pedestrian beacons will be a nice addition, but it would have been much better to square off the turns. Because that “auxiliary” lane on that north leg of westbound Mt Hermon won’t be an auxiliary lane any more, that’s even more of a reason to square off that turn.
  • Lane width: There was some discussion online about width lane. This isn’t a state highway so the California Highway Design Manual doesn’t have to strictly apply, but almost all smaller jurisdictions follow the guidance in this manual, which says you can use eleven foot lanes unless you expect a lot of truck traffic.

    We have a significant volume of logging trucks and gravel quarry trucks pass through town, and the road curves a bit, so I think the eleven foot lanes are probably about as narrow as we should use. The lanes widen to twelve feet east of what’s shown in the drawing, and I’d love to see those narrowed, but that’s outside of the scope of this intersection project. Ditto for the twelve foot lanes on eastbound Mt Hermon.

  • That added third through lane: My initial instinct was opposed to the third lane, but after some thought I think it will improve my safety on a bike and the safety of those walking across Mt Hermon, because right-turning drivers will drive a little slower.

    Westbound Mt Hermon is my daily morning commute. That right-hand lane is currently a very long right-turn only lane, and I get to merge away from that into the through lane. The 85 %tile speed here is 50 MPH, so I must be very assertive in my lane positioning, and even then I still get the willy nillies and the occasional close call.

    With the proposed restriping, drivers will be forced to slow down and merge around my movement. Paradoxically, I think this also improves bike and pedestrian safety on the west side of the intersection, since people turning right from Scotts Valley Drive to westbound Mt Hermon will now have to actually stop and look to ensure the way is clear.

  • Bike lanes: We have bike lanes already on Mt Hermon Road. The project specs green lanes. I think they’re okay for the conflict points, though bike traffic is heavy enough already that drivers mostly know to watch for us. A possible additional is a green lane on southbound Scotts Valley Drive between the right-turn lane and the through lane. A similar through bike lane for northbound Whispering Pines would also be nice. If room is lacking, traffic volume is light enough that sharrows in the through lanes on Whispering Pines and Scotts Valley Drive would be fine, although I don’t believe the city of Scotts Valley has used sharrows before.

    Finally, on eastbound Mt Hermon, a significant percentage of motorists turn right onto Whispering Pines, so I usually sit near the middle of the lane if I’m first in line at a red light so right-turning traffic can easily turn right without hooking me.

  • Bike boxes: I can understand bike boxes for some applications, but I don’t get the point of them for the left turn lanes shown in the diagram. My common practice is indeed to use these left turn lanes, but I and most other cyclists I see just queue up with other traffic.
  • Traffic lights: The city plans to replace the traffic lights at this intersection, which means they’re required by state law to use actuators that detect bicycles and give sufficient time to allow cyclists to cross this very wide intersection. The loop detectors currently in place don’t even detect motorcycles, let along bicycles. The light is also very fast, turning red for my direction after just four seconds, when it takes a moderately strong cyclist coming from a dead stop six seconds to cross this 72 foot intersection.

A Bike Advisory Committee meeting in Santa Cruz

I’m sure there’s more to look at, but these are good starting points for discussion.

This intersection will come up for discussion at the Santa Cruz County Regional Transportation Commission (SCCRTC) Bicycle Advisory Committee (BPC) meeting coming up 6 PM on Monday, June 6, 2016 at the SCCRTC office, 1523 Pacific Ave, Santa Cruz, CA. Other items on the agenda for next Monday’s meeting include:

  • Intro to “User Oriented Transit Planning,” a marketing program to encourage solo drivers to try something different for transportation.
  • A new pamphlet to be published by the RTC: “What Pedestrians and Bicyclists Want Each Other to Know”.
  • County of Santa Cruz’s Draft Striping Plans for Green Bike Lanes .
  • State TDA funding requested for county bikeway maintenance, the Boulder Creek Elementary School Pedestrian Safety Project and the Twin Lakes State Beach/Sanctuary Scenic Trail Project.
  • Preliminary Draft Project List for the 2040 Regional Transportation Plan and 2040 Metropolitan Transportation Plan/Sustainable Communities Strategy.
  • Campaign to close Brookwood Drive to traffic update. Brookwood is that “secret” little one-way road connecting Prospect Heights north of Highway 1 to the Oak Wood Cemetery and Dominican Hospital at Paul Sweet Drive.
  • North Coast Rail Trail preliminary designs.


  1. How do they determine sufficient time needed to cross the intersection? Is this based on a certain percentage of measured crossing times? Is it 8 to 80 based?

  2. Totally agree that safety statement is a cop-out. Want to improve safety for school children? Take out the slip lanes, and maybe add a ‘no right on red’ sign. And driver frustration leading to road rage against bicyclists and pedestrians? Yeah, right. Driver frustration typically leads to horn honking while sitting in traffic, and not much else. (It’s speeding and driver inattentiveness that leads to vulnerable user danger, mainly).

    I’m glad you brought up the light timing issue. When I saw you mention that Mt. Herman is prioritized and has signal actuation, first thing that came to my mind is that means SVD yellow light is probably like 3-4 seconds long, about the minimum allowable by CA law. Not sure if that’s the direction you were talking about, but I see this all over the bay area, and even on two designated bike routes (Forbes and Pomeroy) that cross “prioritized” roads (Kiely and Homestead, respectively) here in Santa Clara. (I personally suspect a short yellow is to blame for that fellow killed while taking a left across E. Fremont in Sunnyvale not long ago, who was reported by witnesses as “running the red light”).

  3. See Caltrans Policy Direction 09-06, which defines a “Reference Bicycle Wheel” (which is a 20″ BMX wheel), and the minimum green + yellow interval is 6 seconds + (distance / 14.7). 14.7 is from 14.7 feet per second, which is 10 MPH, which works out to roughly one extra second for each wide lane you need to cross on a bike on top of the six second start.

    For those who can’t travel 10 MPH, they’ll probably be over by the sidewalk pushing the pedestrian recall button anyway.

  4. …and the 20 inch BMX wheel was chosen as the reference because they found those are the most difficult metal wheels to detect, even more difficult than skinny road hoops.

  5. The traffic engineer that did the striping does not seem to understand the CVC. According to CVC, the bike lane already functions as a right-turn lane for cars. Thus, it makes no sense to have a right/thru lane (Mt Hernon, eastbound?) next to it, because cars turning right should be merging into the bike lane. At best, the right-hand arrow is redundant, and at worse will cause right-hook crashes.

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