continuous flow intersection

Continuous Flow Intersection

March, 2007

Why are we here?

Discuss Continuous Flow Intersection compared to Standard IntersectionUpdate permit statusAnswer your questions

What is this and why?

CFI Benefits

CFI is an at-grade design that provides comparable levels of vehicular flow to grade-separated interchanges at a fraction of the cost—and dramatic, long-term improvements over conventional at-grade approaches – ABMB Engineers

Benefits of CFI

Improved Level of Service (LOS) Less Delay Increased Capacity More Mainline Green Time Existing: 80 sec out of 150, 53% Traditional: 54 sec out of 115, 47% CFI: 74 sec out of 115, 64%

Benefits of CFI

Provides relief to entire system 141 @ Gravois (MO 30) 141 @ Gravois Bluffs Overall LOS D reduced LOS C

Lower cost than grade separation More consecutive movements

Level Of Service

Basically, average time each vehicle is stopped at a signal

Level Of Service - 2010

Existing (current): LOS C, Delay 24.6 sec/veh

Traditional LOS D, Delay 35.4 sec/veh

CFI LOS B, Delay 17.3 sec/veh

Level Of Service - 2030

25% Increase in TrafficTraditional LOS F, Delay 110.1 sec/veh

CFI LOS C, Delay 29.5 sec/veh

Level Of Service - 2030

WB PM Peak Hour - 2,890 veh/hrTraditional Delay 110.1 sec/veh => 88.4 hours

CFI Delay 29.5 sec/veh => 23.7 hours

Consultant’s Conclusion “Both types of intersection configurations

studied (continuous flow, dual lefts)…will provide the necessary capacity to accommodate the projected 2010 peak hour volumes. However, the dual left-turn lane concept would operated to LOS F during peak hours, whereas the continuous flow intersection concept would operate at LOS C during these hours. Therefore, the latter configuration would accommodate greater thru traffic volumes along Hwy 30 in the future.”

How Does It Work?

CFI Left Turns

CFI Cycle

Traditional Cycle

Questions?

Contact Information:

MoDOT Customer Service 1-888-ASK-MODOT