Editor’s note: These comments refer to the article “Proposed Main Street bike lane raises safety concerns” from the Oct. 16 issue (Page 9), in which Ed Harrow was quoted extensively.

To the Editor:

I hope you will entertain my attempt to clarify several points.

As there is no similar bike lane in the US; at least neither VHB, nor MassDOT, nor I have been able to locate one, it makes finding statistics relating to the proposed bike lane rather difficult.

However:

• Over the distance of approximately eight-tenths of a mile, this bike lane will be crossed approximately 30 times by streets and driveways. The Insurance Institute for Highway Safety, in a study published in August of this year notes: “Two-way protected bike lanes raised from the road were crossed by driveways, alleys, exit ramps, or intersecting roads an average of 6 times per mile.”
• With the grade involved, I attempted to find a study that would show the effect of grades upon speed. I did find one, but for cars at highway speeds, and only a 3 percent grade, not a 6.75 percent grade. The study found cars sped up about 8 percent when traveling down a 3 percent grade. On my bike, just coasting, from the bank to the drug store parking lot (where I had to brake to avoid a collision with an inattentive motorist) I reached 17 mph.
• Massachusetts has published a bike-lane handbook, MassDOT Separated Bike Lane Planning & Design Guide. It notes, in Exhibit 4J on Page 64 what is called “Approach Clear Space.” This is the distance from intersecting driveways and streets where parking should not be allowed alongside a bike lane. The slowest car speed specified is 10 mph, requiring 40 feet of “clear space.” I do not believe the planned parking on the southerly side of Main Street meets the spirit of the requirements of Exhibit 4J; I believe doing so would significantly reduce the number of parking spaces.
• Several studies on “inattentional blindness” have been done, the most well known in 1975. It explains why we don’t see bicycles and motorcycles when they are in plain sight, and where they are expected to be. This planned bike lane violates both of those as bicycles will be at least partially blocked by parked cars, and potentially traveling in an unexpected direction, increasing the likelihood of car/bicycle collision.

— Ed Harrow, Hopkinton