St. Charles County Transportation Plan 2030 - East-West Gateway ...

I-70 west of U.S. 40/61 to Pearce Blvd. has four lanes and handles about 72,000 vehicles and 7,200
during the peak hours. Traffic volumes are about 1,900 vehicles per lane in the peak direction of
travel, eastbound in the morning and westbound in the afternoon. Factoring gives 2,100 pcphpl.
With only four lanes, traffic is dense, speeds lower, and the v/c ratio near 1.00 or LOS E.
From Pearce Blvd. to Warren County, the speed limit rises to 65 mph on four lanes. Traffic volumes
are around 56,000 a day. The peak hour volumes are about the same at 2,900 and the directional
split is 55/45. This results in 1,450 vehicles per lane. Factoring gives a pcphpl of 1,600 which is
equal to LOS C.
I-70 Summary
Most of I-70 across St. Charles County operates at or near capacity during the morning and
afternoon peak hours. This is aggravated by the high percent of commercial vehicles. A number
of sections, most notably from Earth City Dr. across the Missouri River to Rt. 94, are operating with
volumes in excess of capacity, LOS F, with serious congestion occurring eastbound in the morning
and westbound in the afternoon. Even though traffic volumes drop at Rt. 94, so do traffic lanes,
resulting in operating conditions of LOS E west past the Cave Springs Rd. interchange. The section
between Rt. 370 and Rt. 79 has serious operating deficiencies, especially during the morning peak
hour, with severe weaving problems that causes operating conditions of LOS F for eastbound traffic
as far west as Bryan Rd. It is only west of there that conditions improve to LOS D. New
construction through the U.S. 40/61 interchange provides six lanes all the way to Rt. Z. To the west,
it remains four lanes with traffic reaching the roads capacity to Pearce Blvd. West to Warren
County volumes drop and operating conditions improve to LOS D.
A major operating problem on I-70 has been traffic flow at many of the interchanges. From the Fifth
St. interchange west through the Rt. 79 interchange, traffic is operating at LOS E and F during the
morning and afternoon peak hours. At many locations, traffic backs up on the off ramps and extends
into the through traffic lanes. This creates a very serious safety problems. With increased activity
expected at all of the interchanges, and increases in traffic volumes, this situation will only get
worse. This is discussed later in the chapter on forecasted traffic.
Rt. 364
Rt. 364 is a Freeway with a speed limit of 60 mph. It is ten lanes across the Missouri River and
eight lanes from Rt. 94 at Muegge Rd. to Rt. 94 just north of Harvester Rd. It handles about 50,000
vehicles a day and 6,000 in the peak hours. During the morning eastbound traffic across the
Missouri River is about 3,600 vehicles. On five lanes this amounts to only 720 vehicles per lane.
Truck percent on this road are low and conditions are ideal. As a result, pcphpl are still well below
1,000 and the road operates at LOS B. Along the section with Rt. 94, it has about the same volume
with traffic per lane at around 800 providing LOS B.
41