October 5, 2007

Exit 22 on the Northbound Henry Hudson Parkway -- Bronx NY

After 9 years of keeping track of the comings and goings of the yellow arrow signs there will be no further updates. Pay attention. Drive safely.

The yellow arrow signs are hit regularly by cars that overshoot the short exit ramp. Notice the tire marks on the curb. The center sign is lying down on the ground.

Driveby 8 July 2007. Click here to see the movie, a 658kB .wmv file. In this clip only the left sign is standing. The other two are down.

To see an overhead vew of Exit 22 click on this link to Google Maps. The last time I looked at the Google Maps image there were three sign shadows visible.

In Google Street View different images show the signs in different states. Google Maps changes images occasionally so I'm not positive that these comments apply to the current images.

The quantity of accidents has to be guessed. Some accidents don't knock down a sign. Some accidents knock down two or three signs. In roughly 14.5 months roughly 16 accidents happened that resulted in the loss of at least one sign, which is about one accident every 27 days. We don't have a way of counting how many accidents happened that would have knocked down a sign if the sign wasn't down already.

My neighbors guess that there are more Exit-22 accidents in winter than summer. Proposed reasons include: fewer total daylight hours per day; winter weather like ice and snow; daily peak use times occurring in the dark rather than in daylight; daylight savings time; seasonal affective disorder; snowplows taking out the signs as they take out the snow; reduced traffic in summer because people are on vacation; reduced traffic in summer because children aren't being driven to school; and some sillier reasons. The comings and goings of the signs reported here -- informal as this may be -- weakly support the idea that there are seasonal variations. Tallied in mid-May 2011, in four years the total quantity of accidents during the six warmer months from April to September is 18 (3 per month) while the quantity during the six colder months from October to March is 30 (5 per month). The high-accident months are December, January, February, March, and May with an average of 5.8 accidents per month, and the low-accident months are April, June and September with an average of 2.0 accidents per month. Even though the sample is small it looks like the seasonal difference might be statistically significant.

The total quantity of accidents per year is decreasing. One possible reason is that the 252nd Street bridge reopened after being closed several years for repairs, allowing traffic to use Exit 21 instead of Exit 22 to get to 252nd Street. Another possible reason is that the Exit 22 signage on the Henry Hudson Highway improved, giving slightly better warning of the abrupt exit ahead.

There's a hint that the signs might get replaced on or near the first of the month, but not exclusively and only a vague hint.

Moving 3-month accident total over time. A 6 on this graph means 6 accidents in 3 months, or an average of 2 accidents a month.

As of 2013-07-02 the total number of signs hit is 87.

Proposed Sign

Other Proposed Sign