TRAFFIC IMPACTS OF OAKWOOD COMMONS

If the proposed Oakwood Commons shopping center is built, how will it affect traffic on Warrensville Center Road and in adjacent neighborhoods? There are too many unknowns to answer with certainty, but we can use standard traffic-flow estimation factors to make a few general predictions.

The conceptual design for Oakwood Commons shows a primary customer entrance/exit on Warrensville across from Stonehaven Road, and a secondary entrance/exit near the southern boundary of the development.[1] The primary entrance/exit would have a traffic signal, while the secondary one would not. A traffic island would permit only right turns into and out of Stonehaven. The secondary entrance/exit would permit only right turns into and out of Oakwood Commons.

Traffic Volume

A recent weekday count of traffic along Warrensville for the afternoon rush hour (the so-called peak hour from 4:45PM to 5:45PM) found 908 northbound and 830 southbound vehicles, for a total of 908 + 830 = 1738 peak-hour trips.[2] 

During the peak hour, a shopping center the size of Oakwood Commons would generate an estimated 1401 trips into or out of its parking area.[3,4,5,6] Of these 1401 trips, 925 would be new trips (that is, trips specifically undertaken to visit the shopping center) and 476 would be pass-by trips (visits by people who would have passed by the shopping center anyway). Thus, if Oakwood Commons is built, the peak-hour traffic volume on Warrensville would increase from 1738 trips to 1738 + 925 = 2663 trips. This is a 53% increase in rush hour traffic volume.

A similar estimate can be done for average daily (24 hour) weekday traffic volume. The current daily volume on Warrensville is about 16025 trips.[8] The shopping center would generate 14610 trips per day into or out of its parking area, with 9643 of these new trips.[3,4,5,6] Thus, if Oakwood Commons is built, the average daily traffic volume on Warrensville would increase from 16025 trips to 16025 + 9643 = 25668 trips. This is a 60% increase in average daily traffic volume.

Intersection at Warrensville and Stonehaven

The primary entrance/exit of Oakwood Commons would require a number of dedicated turn lanes and a traffic signal. A possible configuration of this intersection (based on the developer’s conceptual design[1]) is shown.

We may view this intersection as the crossing of two busy roads, one (Warrensville) carrying 1738 peak-hour trips and another (the shopping center access) carrying 1401. To accommodate left turns, the traffic signal would have to sequence through (at least) three phases.[9] 

There are currently no traffic signals on the 0.9 mile segment of Warrensville between Mayfield and East Antisdale, and traffic flow along this stretch is smooth even during the peak hour. If Oakwood Commons is built, this would change: passing the shopping center during the peak hour would be like crossing a busy intersection with a multi-phase traffic signal. 

A McDonald’s Restaurant is being constructed on Warrensville just south of Cedar (in University Heights between Lansdale and Bushnell), and the Cedar Center North shopping center (at the north-west corner of the Cedar-Warrensville intersection) is being redeveloped. These new businesses will certainly increase traffic volume on Warrensville. Hence, the projections given above must be regarded as optimistic.

Cut-Through Traffic

A traffic study primarily focused on cut-through traffic in the neighborhoods surrounding Oakwood Commons has been published.[10] This report discusses various traffic calming measures which could be considered if cut-through traffic becomes a problem. The only traffic calming measure currently planned is a traffic island at the mouth of Stonehaven, permitting only right-turn access to and from Warrensville.

Prediction of cut-through traffic is difficult, and the developer would put aside funds to cover some traffic calming measures, should they prove necessary.[10] Traffic count surveys would be performed before and after construction of Oakwood Commons in order to identify problems.[10]

References

[1] Conceptual design for Oakwood Commons. (hyperlink)

[2] Traffic count conducted for Warrensville Center Road by Citizens for Oakwood personnel. The count occurred on a weekday (October 7, 2011) from 4:45PM to 5:45PM at a location just south of Stonehaven Road.

[3] Application for rezoning submitted by FISE to the City of South Euclid (2010). The projected size of Oakwood Commons is 325,000 square feet. (hyperlink)

[4] Institute of Transportation Engineers Trip Generation, 8th Edition. Source of trip generation rates.

[5] Institute of Transportation Engineers Trip Generation Handbook, 2nd Edition. Source of pass-by rates.

[6] Trip Generation 8th Edition Spreadsheet, encapsulating data from references [4] and [5]. The generic category Shopping Center (ITE code 820) was chosen for this analysis, since FISE has not specified the Oakwood Commons tenants. If one or more of the anchors are discount superstores, then the number of actual trips is likely to be higher than our estimates.[7] (hyperlink)

[7] Discount Superstore Trip Generation, ITE Journal (2009). (hyperlink)

[8] NOACA Cuyahoga County Highway Traffic Counts (2004). Weekday daily count for Warrensville was estimated as the mean of the counts just south of Mayfield and just north of Cedar: (16350 + 15700) / 2 = 16025. (hyperlink)

[9] Motorists turning left into the shopping center would need a dedicated traffic signal phase. Pedestrians, when present, might also require a dedicated phase.

[10] Oakwood Commons Traffic Impact Report, prepared by Stephen Hovancsek & Associates. (hyperlink)