Daniel Convissor's Web Site

Removing Motorists From Central Park Will Ease Traffic Congestion

Analysis of Central Park Drives Alternate Use Study

I, on behalf of Transportation Alternatives (TA), obtained and analyzed the traffic data the DOT used to produce their report. We compared Scenario 1(the existing conditions) with Scenario 2 (closing the Central Park loop road) and noted the differences between the two. From the data, we found several positive results.

No Dire Consequences
The DOT found 6 intersection approaches will operate at a level of service F, which is the worst traffic rating possible. Considering the DOT studied 132 approaches and there are 1,470 intersection approaches in the study area, 6 is not much.

Traffic Volume Reduced
The number of vehicles counted in the study area decreases if the loop road is closed to them. In the morning peak-hour, the traffic volume shrinks by 4%. The evening peak-hour shows a 3% reduction. These trips are projected to move outside the study area.

No Significant Change in Average Volume/Capacity Ratio
Comparing the average volume/capacity ratio in the morning, Scenario 1 is at .591, while Scenario 2 is .596. The evening rush v/c ratio is .597 in Scenario 1, and .599 in Scenario 2. Volume/Capacity ratio is used to measure the ease of traffic flow in an intersection. Volume/Capacity ratio is determined by dividing the volume of traffic moving through an intersection by the number of vehicles that can move through the intersection. For example, .022 is smooth flowing and .953 is congested.

Majority of Intersections Unscathed
The v/c ratio doesn't change or is improved in over half of the intersections. In fact, 13 intersections show major traffic flow improvements.

Traffic Displaced to Locations That Can Handle It
Intersections with high volume/capacity ratios get small increases in traffic. The intersections that get major increases in traffic now have low volume/capacity ratios.

Flaws in Study

Proper Education Necessary
This study envisioned many people driving all the way to the park and then realizing that it was closed to them, an absurd hypothesis. Drivers' choice of routes are easily changeable.

The Study Only Examined Motor Vehicle Behavior
We need to understand not only the routes which displaced motorists will take, but which modes they switch to. In addition we need to know what effects less cars will have on the modal choices of non-motorists. The study must examine the number of persons using every mode of transportation.

Critical Intersections Left Out
The intersection approaches at 7 Av and Central Park South are not examined. These intersections have been observed by us operating at Level of Service F in the AM peak hour, so removing traffic from Central Park will eliminate traffic problems there.

In addition, Times and Herald Squares were not studied. Since no cars will be coming out of Central Park onto 7 Av or heading for the park on 6 Av, traffic flow in these critical intersections will improve.

Volumes Not Reduced Where They Should Have Been
The DOT did not reduce traffic in many intersections even though closing the park would do so. The study showed all exits from the park loop road as having traffic on them. Intersections leading to and from the loop drive show no decrease in traffic.

Capacity Not Increased Where It Should Have Been
Since no cars are moving into and out of the park, it is easier for vehicles not going to the park to get through the intersection. The study made no point of this.

Corrections

These corrections still do not take into account the significant shrinkage that will take place if the loop roads are closed.

• Volume reduced by 100%
  • Lenox @ 110 St (NB)
  • Adam Clayton Powell Jr Blvd @ 110 St (NB)
  • 72 St @ Central Park West (WB)
  • 72 St @ 5 Av (EB)
• Volume reduced by 15%
  • 72 St
• Volume reduced by 10%
  • Lenox Av
  • Adam Clayton Powell Jr Blvd
• Capacity increased by 1%
  • 5 Av @ 72 St (SB)
  • Central Park West @ 72 St (NB & SB)
• Capacity increased by 2%
  • Adam Clayton Powell Jr Blvd @ 110 St (SB)
  • Lenox Av @ 110 St (SB)
  • 59 St @ 6 Av (EB & WB)
  • 72 St @ 5 Av (WB)
  • 72 St @ Central Park West (EB)

Traffic Volume Reduced
In the AM peak-hour, traffic in the study area decreases by 6%. The traffic volume in the PM peak-hour is reduced by 5%.

Traffic Flow Improved
The current level of service in the morning rush is .591, and will become .575 under Scenario 2.TA, a 3% improvement. In the evening, the level of service improves by 4%, dropping from .597 to .575. In both the AM and PM peak periods, thirty intersections show major traffic flow improvements. Traffic on all streets leading to and from the park loop road show reductions in traffic.

Conclusion