Your questions, answered

When NYSDOT planned to repave Boston Post Road, it noticed that downtown Larchmont, from Beach to Alden, has an unusually high number of crashes for its traffic. So it added a Complete Streets safety component to the repaving.

In 2024, Larchmont, the Village of Mamaroneck and the Town of Mamaroneck each passed a unanimous resolution asking NYSDOT to extend that work along the full length of Route 1. A big reason was the ten schools along the route, with more than 6,000 students.

It reduces the number of travel lanes. Here, four lanes become three: one travel lane each way, a center lane for left turns, and wider shoulders.

New Jersey's DOT explains road diets in this short video:

Boston Post Road is narrow for four lanes. Its travel lanes are about 9.5 feet wide, against an 11-foot standard. Add frequent left turns, driveways, intersections and people on foot, and the four-lane layout produces both congestion and a high crash count.

Safety

No. The road diet is the safety improvement, and it stands on its own. Ossining and Rye both adopted road diets for safety without adding bike lanes.

It is also one of the most effective safety treatments there is for a road like this one. FHWA puts the crash reduction from a four-to-three conversion at 19 to 47 percent, along the whole length of the street. The only common treatment that does better is a roundabout, which cuts fatal and injury crashes by 78% where it replaces a traffic signal and 82% where it replaces a stop sign — but a roundabout fixes one intersection. A road diet works over the entire corridor.

Peter Lagerwey, who ran Seattle’s pedestrian and bicycle program while the city built dozens of them, put it this way: “There are at least 50 to 60 standard traffic operation tools that we have to reduce crashes. Getting close to a 30 percent crash reduction factor is a really high number in terms of the effectiveness of a particular treatment.”

Here, dropping to three lanes frees enough width for wider travel lanes and also a continuous bike lane. The bike lane is a benefit of that space, not the reason for the project.

Yes, hundreds of times. Virginia counted 66 built in that one state since 2010, and Seattle has installed more than 29 since 1972. Towns that build one tend to build more: Ossining, Fairfield and Rye have each come back for another.

The nearby examples, with Street View and studies

A four-lane undivided road doesn't work like four free-flowing lanes. Whenever someone stops to turn left, one of the two lanes in that direction is blocked, and everyone else has to merge around. Three lanes put turning drivers in their own center lane and leave one continuous lane each way. The Federal Highway Administration has found this can improve traffic on roads of the right size while making them much safer.

Watch the simulation

NYSDOT tested exactly that with local traffic counts and turning movements. Its analysis shows the three-lane design handles today's traffic and generally maintains or improves flow. The exception is the Orienta Avenue intersection, which already has a problem and is being studied for a bigger redesign.

Traffic

About two years of work: turn counts at every signalized intersection, traffic modeling, and study of the corridor's geography.

The whole length of Boston Post Road gets dedicated space for left turns, instead of drivers waiting in a travel lane. At the busiest intersections, such as Hommocks Road and Harbor Island, there are dedicated right-turn lanes, and more can be added where they're needed.

Traffic

The center turn lane gives emergency vehicles a clear path around traffic, while drivers pull to the right. FHWA found road diets do not slow emergency response. In Woodbury, New Jersey, police opposed a road diet at first; afterward, the retired police chief said it did not affect response times.

Emergency response

Not on the Post Road. Daily traffic hasn't grown in 45 years, and it dropped after 2019. What has grown is the school-run peak.

What drives traffic

Yes. The Federal Highway Administration lists four-to-three road diets as a proven safety countermeasure. Studies it cites found 19% to 47% fewer crashes overall, including fewer rear-end, left-turn and sideswipe crashes. Those are mostly crashes between cars, so drivers get most of the benefit.

Safety

From 2015 to 2025, 46 cyclists and 44 pedestrians were hit by cars on Boston Post Road. The crashes cluster around the schools.

See the map

Children, most of all. In the 2025 Mamaroneck and Rye Neck Safe Routes to School parent survey, about 40% of students walk to school and 20% bike. Safer crossings, sidewalks and bike space make those trips safer and give more families the option to leave the car at home.

A parking-protected bike lane needs about three more feet of buffer, so that a door opening into the lane doesn't hit a rider. That extra width isn't available on Boston Post Road. Keeping the parking means the bike lane runs on the travel side instead.

Parking & business

Most of it stays. Some spaces would be removed or moved where the room is needed for safety: longer bus stops, better sight lines at intersections, and curb extensions for people crossing. NYSDOT is still refining the parking layout.

Parking & business

Federal and New York State transportation funds. The budget is $19.5 million, and there's no local contribution.

Process

NYSDOT showed several roundabout concepts to get feedback. They aren't part of the main plan yet. The one at Orienta is the most likely to be included, because it addresses a long-standing traffic problem there.

NYSDOT expects construction to start in 2028 or 2029.

No. NYSDOT lists the project as "In Development." It has shown alternatives at two open houses and keeps refining the design based on engineering and public input.

Because the state is already rebuilding and restriping the road. That makes this a rare chance to fix known safety problems at the same time, and for free.

NYSDOT held open houses in June 2025 and April 2026. A third public meeting is expected this fall. You can also sign the petition and email your officials.

Take action

On NYSDOT's project page.

Volunteers with Mamaroneck and Rye Neck Safe Routes to School, who have followed the Boston Post Road redesign for three years. We don't speak for NYSDOT or the municipalities. We built this because NYSDOT's plan deserves a fuller explanation than it has had.