Problem 6: Route 146 Arterial Study

1
Problem 6 Route 146 Arterial Study 
Were going to look at 7 intersections
simultaneously the Shenendehowa Campus entrance,
Moe Road, Maxwell Drive, Clifton Country Road,
the unsignalized west side of the I-87
Interchange, the signalized east side (including
Fire Road), and Route 9.
2

• We will focus on the PM peak hour. (PM with-site
  condition)
• The intersection counts and signal timings weve
  obtained will be used as basic inputs to create a
  TRANSYT7-F (Version 9.5) simulation dataset.
• We will exercise TRANSYT7-F in simulation mode to
  see how it thinks the network is performing.
• Finally, we will use it to optimize the
  performance of the network as a coordinated
  system.

3
(No Transcript)
4
What are the typical data requirements for this
type of analysis?

• Saturation flow rates for each lane group
• Volumes for each lane group
• Signal timing plans (consistent with the HCM
  input datasets)
• Distances between the intersections
• Link-to-link movement patterns
• Minimum phase lengths
• Opposing links for the permitted lefts and the
  right turns that can move when there is no
  competing traffic, as at Clifton Country Road
  northbound

5
HCM from the HCM analysis
Timings From
T7F1 hand-generated input to TRANSYT7-F to get
acceptable v/c ratios for all of the lane groups
T7F2 developed by TRANSYT-7F when it
optimized coordinated operation across the
network
6
At what locations were substantial timing changes
necessary to improve the v/c ratio between the
HCM and T7F1?
Maxwell Drive and only for phases 1 and 3, all
the others were very closely aligned!!!
Other observations?
7
What have we learned?

• The HCM analyses prepared us quite well for the
  network analysis.
• TRANSYT-7F was able to improve the performance of
  the system (delay-wise) by only about 8, when it
  optimized the signal timings.
• The way the HCM treats these intersections is
  very similar to the way they are treated in
  TRANSYT-7F. The two analytical methods expect
  very similar inputs, treat the problem in similar
  ways, and produce similar outputs.
• The one major difference between the HCM and
  models like TRANSYT-7F is that the capacities of
  the saturation flow rates are derived by the HCM,
  whereas they are inputs in the case of
  TRANSYT-7F.
• Oftentimes, it helps to do the HCM analyses first
  and get credible saturation flow rates for the
  various lane groups before starting a TRANSYT-7F
  analysis.