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

B-1.4 MoDOT and County Crash Rate Comparison
For a better review of safety on the major roads in St. Charles County, the three crash indicators
discussed above for MoDOT roads and County roads were compared. For crashes per mile,
MoDOT averaged 131 crashes per mile for their 44 road segments while the County averaged 32
for their 24 road segments. For the severity rating, MoDOT had an average value of 76 while the
County had 12. For the crash rate, MoDOT had an average of 327 while the County had 178.
It can be seen that in all three categories the ratings on MoDOT roads are much higher. This tends
to indicate that travel on MoDOT roads is not as safe as travel on County roads. However, the best
measure or safety on a road segment is the crash rate as it uses the number of crashes along with the
traffic volumes and the length of the segment. In order to best assess how MoDOT roads and major
County roads compared, a composite crash table using crash rates was developed and is shown on
Table 26. It ranked 58 road segments leaving out roads that had a crash rate under 100. It shows
the distribution of the major roads regardless of whether they were MoDOT roads or County roads.
MoDOT had the higher number of road segments because they carry the highest traffic and have the
most crashes. They contained 178 miles and the County had 40 miles resulting in 82% for MoDOT
and 18% for the County. The composite list shows MoDOT had the most crashes with 15,420 while
the County had 1,727, totaling 17,147. This is 90 percent and 10 percent respectively. Multiplying
the miles by the ADTs, reveals that MoDOT roads handled 5.3 million vehicle miles of travel
(VMT) a day while the County roads only handle 0.6 million. This places MoDOT’s VMT at 90
percent and the County’s at 10 percent. This reflects the number of crashes on each road system.
Examination of Table 26 reveals that the first 10 roads listed are MoDOT roads. At the top of the
list was Rt. 94 from Rt. 370 to I-70. The next highest include other segments of Rt. 94, the two
segments of Rt. K from I-70 to I-64, and segments of Rt. N and Rt. Z. Mexico Rd. from Mid Rivers
Mall Dr. to Rt. K was number 11. It was followed by four more MoDOT roads including three more
segments of Rt. 94. The next County road was Zumbehl Rd. from I-70 to Rt. 94 which ranked
number 16. Five County roads, including the other three segments of Mexico Rd., were in the
middle ranking 19 through 23. The remaining County roads were scattered throughout the list. In
all, the MoDOT road segments had the highest crash rates.
Although MoDOT roads have the highest crash rates, it must be noted that I-70 ranked low on the
list. Their was only one segment, U.S. 40/61 to Pearce Blvd. that was above the middle of the list
(number 18) and it was below two County roads, Mexico Rd. from Mid Rivers Mall Dr. to Rt. K,
(number 11) and Zumbehl Rd. from I-70 to Rt. 94 (number 16). Eleven segments of I-70, that
included those with the highest traffic volumes in the County, ranked low on the list.
The road with the worst crash rating overall in St. Charles County was Rt. 94. Many segments,
especially those between I-70 and I-64, had very high crash rates. This road has been undergoing
upgrading with the construction of the Rt. 364 freeway from approximately Hemsath Rd. west to
Harvester Rd. and other sections to the west of it are scheduled for construction . This will greatly
alleviate some of the safety problems presently being experienced.
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