The scene is the Alpine Trail, a high, narrow, rocky path running along the south side of Alpine Road in Portola Valley.
Heading east on bicycles are a couple of students from Corte Madera Middle School. They're on their way to the Alpine Hills Swim & Tennis Club for after-school lessons and are using the trail to avoid the heavy and dangerous vehicle traffic on the road, which is a few feet to the left and steeply lower by as much as 10 or 12 feet.
Heading west on the trail are two people on horses.
The cyclists and equestrians meet. A dicey situation at best. Unpleasantness may follow.
The uphill side of this 0.9-mile stretch of trail is fenced pasture; the other side is unfenced with near vertical drops to the road. If a horse spooks, there's nowhere for it to go, said equestrian Ellie Ferrari, who recently walked this trail with her fellow Trails Committee members.
To prevent such scenarios, a majority on the Trails Committee does not want to see bicycles on this trail. "We suggested that it was not the right mix," Ms. Ferrari said in an interview.
But a coalition of town residents interested in "safe routes to school" want bikes and kids on this trail. Students cross just one street -- Los Trancos Road -- to get to the club to be picked-up or to have a snack or a lesson.
Kids are taking that route already, but they're using the bike lane rather than the trail, perhaps because the small rocks interfere with the wheels on their book bags, Councilman Ted Driscoll said recently.
When asked to comment on a spooked horse having nowhere to go, Mr. Driscoll said in an interview: "I guess that's true. In the end, there's going to be a conflict if we end up using our trails as a commute opportunity for our kids" and for equestrian recreation. "That's a problem we're going to face in the future and I'm not sure what the solution is," he said.
At the June 9 Town Council meeting, Mr. Driscoll recommended giving the Trails Committee some attention to "see if that advisory body is giving us the advice we need."
There may be 100 horses in town, Mr. Driscoll told The Almanac, but there are 1,000 kids. (For the record, Portola Valley has 740 enrolled students and 249 registered horses, according to officials.)
Biking students, Ms. Ferrari pointed out, can use the paved trail on the north side of Alpine Road. But that route has them crossing Alpine Road twice, Councilwoman Maryann Derwin said in an interview.
Equestrians should simply avoid the south-side trail during times when students are likely to be on it, Ms. Derwin said.
Since August, a task force has met four times to explore ways to get families to stop driving kids to school and have them bike or walk instead. It would also help the town toward its stated goal of reducing greenhouse gas emissions.
Members of the Trails and Traffic committees were invited to the task force meetings, and two Trails members came to one, Planning Manager Leslie Lambert told The Almanac. Chris Buja, the Traffic Committee chair, said he has been too busy starting a company to attend.
The tentative plan is to have a "safe routes" program ready by September, Ms. Lambert said.
An ad hoc committee composed of a broad cross-section of town residents will work toward that goal.
The town has turned to six such committees in the last five years, according to Assistant Town Manager Janet McDougall. The groups have addressed matters such as dogs on the Coalmine Ridge trail system, an upgrade to Triangle Park, and the best use of the Spring Down property.