Newton is refusing to address obvious opportunities to make our streets safer for pedestrians. I discussed this in the context of Adams St. in Nonantum (herehere, and here). A soon-to-be missed opportunity is the upcoming repaving of Chestnut St. from Collins Rd. to Elliot St. Nearly every intersection with a side street should be narrowed to reduce the speed of cars and trucks turning onto the side streets and to reduce the time pedestrians spend in the street, vulnerable to cars. The curb cuts should be re-oriented to direct pedestrians across side streets and not into Chestnut St. There is no indication that either step is being even considered.

Backing up, given the variety of street widths and corner designs, there is no standard intersection in Newton. It is possible, though, to propose a model intersection of a main street and a side street. Until someone identifies a better reference, I propose Parker St. and Daniel St. (Yes, that’s right up the street from my house. If you’re in the neighborhood to check it out, do drop by and say hello.)

Daniel St. is 24′ wide for most of its length. The pedestrian crossing is 34′ (measured at the center of the curb cuts). The distance between the points at which the corners start is 60′. This last measurement give an indication of how tight or gentle the corner is. The tighter the corner, the more vehicles have to slow.

Note: Parker St./Daniel St. is not the ideal intersection. It’s just the best example of a representative intersection that I’ve measured. It could be made a little tighter. Daniel St. is a worthy reference, though, because, as a feeder to Bowen School, it’s as busy as any side street and regularly handles bus, fire truck, garbage truck, moving truck, and any other form of big apparatus. It is completely functional. If you’ve got a better reference, please drop a note in the comments and I’ll go measure.

None of the side-street intersections on the section of Chestnut to be repaved are as tight as the Parker St./Daniel St. They could easily be made as tight in the course of the repaving effort. But, they are not. Once again, the city is failing on its promise to make the city safer for pedestrians.

There are three basic use cases among the Chestnut St. side streets:

  • 24′-wide streets that need tuning
  • 34′-wide streets that need major tuning
  • Outliers

I suspect that the first two use cases are the predominant use cases across the city. We should have a standard design for both.

There are seven 24′-wide streets that intersect with the section of Chestnut St. to be repaved. Four of them have crossings between 36″ and 41′ 6″. One is 34′ 6″. All five of these could be easily tightened to a Daniel St.-like 34 (or maybe even 30′ or 32′) simply by tightening the corners. In practical terms, it means replacing the five or six pieces of granite per corner that define the shape of the corner and rebuilding the sidewalk. There would be no difference where the corners begin and end and the Chestnut Street and side street curbs begins. 

Kodaya St. is the 34′ 6″-wide street. It has a 46′ crossing. The distance between curve start is 91′. Its corner radii — a measure of how tight the corner is (smaller is better) — appear to be about the same as its 24′-wide neighbors. Which means the only reason that the intersection is wider — 35% wider than Daniel St./Parker St. — is that it’s a wider side street.

There is a growing recognition that wider streets lead to higher speeds. Higher speeds are more dangerous for a variety of reasons. Walking along streets with higher speeds is less pleasant, so higher speeds discourage pedestrian activity. But, the width of Kodaya is not a problem that can be cured in the course of the Chestnut St. repaving. 

What can be cured in the course of the Chestnut St. repaving is the excessively long pedestrian crossing at Kodaya. Wider streets mean wider travel lanes. At the intersection, wider travel lanes mean, in addition to a longer crossing, that cars have more room to turn, which leads to higher cornering speeds.

The way to address the problem at Kodaya (and similarly wide streets across Newton) is to extend the curbs to create a Daniel St.-like 34′ or less crossing. The treatment would be similar to the curb extensions on Centre St. in Newton Centre. There is simply no reason why similar side streets off the same main street should have wildly different pedestrian crossings, even (or especially!) if the street width is different. Look at how much narrower the crossing at Amherst St. is compared to Kodaya. Look at how much street space is below the car in the Kodaya St. intersection in the picture. 

While there is only one 30’+ side street between Collins and Elliot, there are plenty of examples around Newton. The city should have a standard treatment for these during repaving projects. It should reflect that, as proven on Daniel St., that vehicular traffic doesn’t need more than a 34′ opening to get onto and off of a major street like Parker St.

There are three significant outlier intersections on this stretch of Chestnut St.: Collins Rd., Tamworth Rd., and Summer St.  Collins Rd. is a unique case. It’s 24′ wide and winds down a steep hill as it approaches Chestnut St. It feels like the intersection — 44′, 30% wider than our reference 34′ — is overly wide, but it’s a more complex case than your humble scribe feels comfortable evaluating.

Tamworth Rd. and Summer St., on the other hand, are clear and obvious disasters. If the city is not fixing intersections like these, it just isn’t serious about pedestrian safety.

Summer St. is 25′ 6″ wide. The crossing is 59′ 9″. Tamworth Rd. is 24′ wide. The crossing is 53′ wide. I’ll do the math for you: the pedestrian crossing at Summer St. is 134% wider than the road width once the corner straightens. For Tamworth Rd., it’s 121%. There is simply no justification for crossings that wide. They are unsafe. They leave pedestrians in the road for too long. And they encourage hide speeds through the intersection — where pedestrians are supposed to cross — and on the side roads.

Both Summer St. and Tamworth St. should and could be tightened … significantly.

Almost all of the corners in the stretch of Chestnut to be repaved have diagonal curb cuts — curb cuts that are at 45° angles to the pedestrian crossings, either across the side street or across Chestnut St. These diagonal curb cuts are cheaper, you only need one per corner, even where there is a crossing across both streets. But, they are not as safe or as nice for pedestrians. They need to be aligned with the direction people are walking.

The city sold the override, in part, on the promise that money would be spent making roads safer. So far, not seeing it. Potholed roads are not really unsafe. Potholes bend rims, break suspensions, and ruin tires. But, I’m not aware of any safety issues that bad pavement creates on mostly urban roads. Safety improvements will follow design changes, and the city road improvement program is not making design changes. Wide intersections and misaligned curb cuts are a pure expression of people in cars as the priority over people on foot. That the fix is both obvious and ignored illustrates that the city’s priorities haven’t changed.

 







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