Request for State Road 135 Safety Analysis - March 21, 2006



    Mr. James Ude
    INDOT Planning Department
    Seymour District
    185 Agrico Lane
    Seymour, Indiana 47274

    Subject: Request for State Road 135 Safety Analysis

    Reference:
    1) WRCU 2006-001, Infrastructure Access Optimization, State Road 135
    2) Transportation Research Board Access Management Manual
    3) Wal-Mart Traffic Impact Study, December 2004

    Dear Mr. Ude,

    The members of the White River Citizens United group respectfully request that INDOT
    perform a Safety Analysis of State Road 135. Of particular concern is the segment
    between County Line Road and Smith Valley Road. It is our contention that an excessive
    number of accidents occur in this segment of the road. We believe that the unlimited
    center left turn lane, the lack of right turn deceleration lanes, the excessive number of
    highway access points, and the current traffic volume contribute to an accident rate that is
    above the normally expected rate.

    We have given some independent thought to this safety issue. One segment of our
    analysis is based on data obtained from the Greenwood Police Department. In 2005 they
    processed 2158 total accident reports. Of this, 378 were for accidents on State Road 135
    between County Line Road and Smith Valley Road. Thus, that section of approximately
    1.93 miles of road was responsible for 17.5% of the city’s accident reports. We consider
    that indicative of a public safety concern. In 2004, there were also 365 accidents in this
    same area. The intersection of State Road 135 and Smith Valley Road (County Road
    900N) accounted for 148 accidents (20% of the total) for this two year period.

    A second segment of our analysis is based on the expected accident rate expressed in
    incidents per million vehicle miles as compared to the actual. Page 17, Table 2-2, of the
    Transportation Research Board Access Management Manual indicates that an accident
    rate of 7.9 (accidents/million vehicle miles) is to be expected for a highway having 40 to 60
    access points per mile, and a “two way left turn” center lane configuration. These
    conditions match the configuration of State Road 135 in the region of interest.

    The December 2004 traffic impact study generated in support of the Wal-Mart petition to
    build a store at Smith valley Road and State Road 135 reports in Appendix A, page 5, that
    the 24 hour traffic volume was 33,866 cars. If one assumes this traffic volume constant
    each day of the year, the traffic distance-volume rate is:

    33,866 cars/day X 365 days/yr. X 1.93 miles = 23.86 million vehicle miles/yr.

    The accident rate is:

    A.R. = 378 accidents/yr. / 23.86 mvm/yr. = 15.84 accidents/mvm

    This calculation reveals an accident rate that is twice the expected rate. Again, we
    consider this to be indicative of a public safety concern.

    The TWLTL (Two Way Left Turn Lane) configuration is reported on page 202 of the TRB
    Access Management Manual to be appropriate when average traffic volume is less than
    24,000 vehicles per day. It would then appear that State Road 135 has exceeded its safe
    capacity limits, and the excessive accident rate is the result.

    We look forward to an INDOT Safety Analysis and the resulting recommendations. Please
    advise us if we can be of any assistance.

    Forrest Mellott
    John Griffin

    CC: Rep. W. Burton
    Mr. E. Ferguson
    Rep. D. Frizzell
    Chief J. Pitcher
    Sen. M. Young
    Sen. B. Waltz