Hwy 101 from SW 29th St. to SW 32nd St.Highway Capacity per Design

N

EW

S

Mobility StandardsMaximum Volume to Capacity Ratio

• V/C is the ‘volume’ to ‘capacity’ ratio that measures the functionality of an intersection.

(Analogy – a bucket represents the capacity of a roadway and varying amounts of water as the demand on the roadway. If the bucket is less than half full it is easy to carry and move around. Once the water level reaches the ¾ mark it becomes harder to move without splashing and the person carrying it moves much slower. When the bucket is full it is very hard to move without splashing even taking very small steps (V/C=1). If more water is added, it flows over the sides creating a big mess (V/C >1.0)!)

• Statewide Hwy Non-Freight Routes with posted speed less of 35 mph

or less – 1999 Oregon Highway Plan (OHP) mobility (V/C) standard is 0.85 (the absolute maximum for this vicinity).

• 20 Year Highway Design Manual (HDM) - Mobility Standard for Statewide Hwy (NHS) Non-Freight Routes with posted speed less than 45 mph – maximum V/C ratio is 0.75.

2 Lane 4 Lane• 2007 V/C = 0.79• 2010 V/C = 0.83• (Need V/C < 0.75)HDM* Mobility Standard = 0.75

• 2030 V/C = 1.06• (Need V/C < 0.75)HDM* Mobility Standard = 0.75

2 Lane designInadequate

* HDM – ODOT 2003 Highway Design Manual

• 2007 V/C = 0.48• 2010 V/C = 0.53• (Need V/C < 0.75)HDM* Mobility Standard =

0.75

• 2030 V/C = 0.62• (Need V/C < 0.75)HDM* Mobility Standard =

0.75

4 Lane design Adequate