Friday, May 6, 2011

Downing St. Closure: Will Firefighters Be Delayed Getting to Nick Cuba's Apartment?

Nick Cuba submitted the following post analyzing the potential delay in fire response times should Downing St. be closed as requested by Clark University.
Last fall a multi-million dollar PILOT agreement was announced between Clark University and the City. PILOT funds will be spent in ways that align with Clark’s educational mission and enhance its neighborhood:  supporting the Worcester Public Library and paying for improvements to Main South’s Crystal Park. Additionally, a result of this agreement will be the closing of a stretch of Downing St. which bisects the Clark campus.
Red Line Shows Segment of Downing St. to Be Closed
The City’s press release cites public safety as the reason for the street closing. This segment of street runs between a cluster of Clark dorms and campus features such as the library, cafeteria, and gym, and is crossed by many students over the course of each day. A rising slope and low sun angles during winter seem to raise the risk of accident.

Google Streetview (Looking Southwest) of Southeast End of Proposed Street Closure
Some neighborhood residents have come out in opposition to the road closure. Anticipating a shift of traffic onto nearby streets, and longer travel times on alternate routes, these residents have justified their opposition with a public safety concern of their own. They argue that the street closing will affect Worcester Fire Department’s response times, and that Main South residents, particularly those in the Grand/Kilby/Gardner St. area, would see the response time to fires at their homes increase as a result of the road closure. As a resident of the Grand/Kilby/Gardner St. area, I’m curious if this increased risk is real, and if so what kind of a delay is to be expected.
This type of a question can be answered using ESRI’s Network Analyst software. I designated the Park Ave, Webster Square, and Southbridge St. fire stations as “origin” points, labeled all buildings within Main South as “destination” points, and then measured the distance along a road network between each building and the nearest fire station. I measured this distance once along the current road network, and then again after removing the Downing St. segment from the network. The difference between these before/after distances will predict the delay caused by a closure.

Fire Symbols Show Stations, Yellow Dots Show Destination Points, Blue Line Outlines the Main South Neighborhood and the Red Line Marks the Stretch of Downing St. to be Closed
After the first run I selected only the buildings likely to be responded to by the Park Ave. station, since this is where any delay may be expected. Among these buildings, the longest distance to the Park Ave station is 4,700 feet, or nearly a mile. The map below shows residences close to the Park Ave fire station in blue, gradually changing to orange with distance from the station. 
Building Distance to the Park Ave. Fire Station, Blue (close) to Orange (far). A Sample Route is Shown with Purple Line.
Surprisingly, after I recalculate with the Downing St. segment removed, the resulting distances between buildings and station are in every case the same as before the street closure. The sample route in the map above shows one shortest path which did not route the trucks on Downing St.
Still, such a comparison does not consider the feasibility of using side streets in the area. Presumably it’s possible for fire trucks to access these streets (how else to put out fires there?) yet they may not be desirable as through-ways for fire trucks. In order to account for this scenario I ran the analysis a third time, allowing trucks only to access Main St. and areas south by way of May St. in the north and Maywood St. in the south.
This time we do see some detours from the Park Ave station to some Main South buildings. Additional travel distances range up to 3,400 ft., or more than half a mile, and are concentrated in the Wyman St./Hancock St. area, across Main South and relatively distant from both May and Maywood Sts. Note that these areas are not the farthest from the fire station, but those most heavily affected by detours.
Increase in Travel Distance from the Park Ave. Fire Station Assuming No Use of Side Streets. Pink-Gray Indicates Little/No Increase in Travel Distance, Red Shows Greatest Increase in Travel Distance
 The average additional distance for the 367 buildings on or south of Main St. is 800 ft. The average additional distance for all buildings is 340 ft.  Assuming fire trucks would travel 30 mph on these streets, which lets us convert detours into delays, the results can be summarized:
Avg. Delay
(all buildings)
Avg. Delay
(on/south of Main St. only)
Maximum Delay
Downing St. Closure
Downing St. Closure,
no use of side streets
13 sec.
30 sec.
89 sec.

The above table and map indicate that problematic delays in response time would occur only for fires in a very concentrated geographic area. Delays could be avoided altogether if fire trucks were routed over side streets in the area.
The estimated delay for my own apartment?  18 seconds.

1 comment:

  1. Thanks Nick, there does seem to be some potential delay for residents southeast of Main St. centered around Wyman St.

    Getting an answer as to whether or not fire trucks from the Park Ave. station presently use Downing St. to access these properties seems to be key here in concluding whether or not there will be a delay.

    If fire trucks presently do not use Downing St., and they use May and Maywood Sts. only, then closing Downing St. will not result in any delay.

    If they do, the alternate seems to be to use Charlotte to Woodland to Downing Sts. Lots of 90 degree turns on this alternate route, is this a feasible alternate route (resulting in no delay as your analysis shows) or would fire trucks be limited to just May and Maywood Sts., resulting in the delays your analysis shows.