Spoke Supports Staff Recommendations on MANGo

Re: Support Staff Recommendations on MANGo
MANGo is beauty and equity for the Pico Neighborhood

Dear Mayor Pam O’Connor, Santa Monica City Council members, City Manager Rod Gould, Planning Commissioners, City Staff & Consultant Team,

With overwhelming community support, the city and consulting team have put forward a wonderful project in MANGo. With only one ask we fully support staff recommendations for this beautiful project that we believe will serve the Pico Neighborhood, the community and future generations actively and safely transporting themselves.

We understand there is opposition to the plan from some PNA members, based on simply the mere suggestion of allowing diverters to remain in the tool box. We are not advocating for aggressive implementation and indeed acknowledge diverters may never be needed for this project. With support from many Pico Neighborhood residents and the community we would like them to at least remain as an option. They restore peace in many neighborhoods in all parts of Santa Monica: Centinela and Dorchester, Delaware and Centinela, Cloverfield and Delaware, Exposition and Warwick, Bay, Grant and Pacific at 16th, La Mesa Drive and 26th, 6th and Pico, 24th & 25th streets between Broadway and Santa Monica Blvd plus all the medians that divert traffic.

Santa Monica Spoke supports staffs recommendation for the use of turn restrictions to reduce traffic. That and traffic circles may be all that is necessary to bring traffic levels down to a safe level, and implementation can occur over a course of years. We won’t know what works until we try. We fully understand the fear and controversy surrounding traffic reduction goals and diversion as part of the plan since this is Santa Monica’s first neighborhood greenway. However this cannot be a greenway without true traffic reduction goals. There is considerable experience and general agreement about appropriate maximum Average Daily Trips (ADT) and speed numbers. Staff have suggested an ADT goal of fewer than 2000. The National Association of City Transportation Officials (NACTO), based on research from cities across the US, suggests a goal of fewer than 1500*. Most cities (Portland, San Luis Obispo, Vancouver, BC), aim for a goal of fewer than 500, Long Beach’s greenway has 800-1000 ADT, so fewer than 1500 seems reasonable and achievable. Please see attached “What traffic experts say”

Mathematical characterization from NACTO:

On a 20 mph street with 1,000 vpd*, a cyclist traveling at 12 mph during peak hour would be passed by a car traveling in the same direction approximately every 86 seconds (assuming peak hour is 15 percent of vpd, the street is two-way with 70% of traffic volumes traveling in the peak direction, and cars are evenly spaced along the street). By comparison, at 3,000 vpd, a bicyclist would be passed by a car every 29 seconds, and at 5,000 vpd, a bicyclist would be passed by a car every 17 seconds.
*vehicle per day

 It has been noted that many PNA members live in the Virginia Park area and are among the hundreds of parents using or “abusing” Michigan Avenue to drive their children to Samohi or to access the freeway. We hope you will support prioritizing the local residents and the safety of school children trying to walk and bicycle to Samohi and other schools over the convenience of vehicle drivers and cut through traffic. Change is difficult – but improvements are needed. With Councils leadership we can provide equity and peace to the Pico Neighborhood and safe routes to school for future generations of children by reducing cut-through traffic on Michigan Avenue.

In summary; we are NOT asking for an aggressive implementation of diverters as soon as possible or ever if they are not needed. Other than reducing traffic volumes to less than 1500 ADT we fully support all the other aspects of staff recommendations for the MANGo Plan and feel this will truly be an asset to this community and a visionary template for improving other streets in our city and region. This project’s success hinges on steep traffic reduction and is not a greenway without it. There is no safety or comfort for pedestrians, cyclists or other non-motorized road users without reducing the number of cars on Michigan Ave. MANGo is a big step toward encouraging a change in that thinking of how we get around and can help set the tone for the next fifty years of the way Santa Monica works. What kind of city do we want? One for cars, or one for people?

Please support MANGo and make sure we set an ambitious target for reducing traffic on Michigan Avenue to less than 1500 vehicles per day and assure that we have all the tools at our disposal to achieve safer, healthier more active options for circulating in Santa Monica and regionally.


Cynthia Rose
Santa Monica Spoke
Local Chapter LACBC

*NACTO: http://nacto.org/cities-for-cycling/design-guide/bicycle-boulevards/volume-management/.

What traffic experts say:

From Kay Teschke:
Without low traffic, Greenways fail to protect
One of several surprises in the study: a local street that’s been designated as a “bike route,” with traffic calming such as speed humps, may be more dangerous than other local streets.
In a phone interview, study author Kay Teschke of the University of British Columbia said the reason is that such routes actually become more popular with cars, because they often feature signalized crossings.
In further findings that Teschke hasn’t yet published, she said, her team found one key way to greatly improve traffic safety on a neighborhood greenway: cut auto counts by adding traffic diverters at key intersections.
“We found that if you diverted traffic from the local streets, it was just as good as a cycle track,” Teschke said.

From nationally recognized John Ciccarelli:
In my mind the essence of the neighborhood greenway experience is “full-street passing” (by motorists) of solo and side-by-side (e.g. family) bicyclists, combined with relatively low overtaking speeds (by motorists).  For comfortable full-street passing (i.e. motorist uses the entire remaining width of the street to pass), the oncoming traffic volume must be sufficiently low, and that’s the main factor.

Let’s do a thought experiment with simple math.  Assume a certain block has an ADT of 3,600.  A traffic engineering rule of thumb is that for suburban streets, ADT/10 roughly equals peak-hour volume (PHV), i.e. volume at the busiest hour.  3,600/10 = 360.  Let’s further assume that motor traffic volume in each direction is equal during peak hour, i.e. 180 cars per direction in peak hour.  Let’s even further assume that the cars are spaced evenly, instead of in bursts (“platoons”).  There are 3,600 seconds in an hour, so that’s 1 oncoming car every 20 seconds in each direction past a stationary point.  (A bicyclist’s experience while moving would be different, because closing speed from behind would be lower — longer gaps between potential passers — than ahead.)

From a motorist’s perspective, 20 seconds is tight to execute a safe pass.  Some will rush past, some will pass a bicyclist (let alone two bicyclists riding abreast) too closely, and some will become impatient if enough time elapses without a gap they consider acceptable.

Now let’s cut the ADT, hence the PHV, in half — to 1,800.  Our hypothetical, mathematically perfect street now has 40-second passing gaps.  That’s comfortable for an un-hurried full-street pass.  At 900 ADT the gaps would be 80 seconds — over a minute.  You get the picture.

John Ciccarelli
Bicycle Solutions — Planning, Design, Parking/Storage, Education/Training, Expert Witness
San Francisco, CA
415-912-6999 mobile/text



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