ALDOT Statewide TSMO Program Plan ALDOT Statewide TSMO Program Plan 20190522REV | Page 33

A: Safety
Considering where safety concerns exist and developing
potential solutions to address these concerns is paramount.
ALDOT’s Safety Operations Program, as a part of their
database, regularly updates crash data. The data is available
through an online dashboard called Advanced, dated 2013
through current. An example of the CARE crash data
interface is shown at right with Houston County queried. It
is recommended that regional TSMO engineers analyze
current crash data each year to guide in project
development. Example project recommendations may
include; A.S.A.P. expansion, increased camera coverage,
expanded TMC support, etc.
B: Mobility
B1: Congestion
Mobility is directly correlated to congestion levels and is a key
consideration for project development. It is recommended that
the NPMRDS be utilized to identify corridors of regional
significance that have a higher-than-average level of congestion.
One year of data was pulled for all corridors from September 2017
to September 2018. The Massive Data Downloader Tool was used
to generate reports that included Travel Time Index (TTI). An
analysis of the data was completed to determine average relative
congestion along each corridor. The following TTI thresholds based
on research completed by the University of Alabama (Congestion
Quantification Using the National Performance Management
Research Data Set (Sisiopiku, Rostami-Hosuri, 2017)) were
selected to reflect user perceptions of congestion and its impact
on their travel times and are summarized as follows:
• 1.10 < TTI < 1.50 moderate congestion
• 1.50 < TTI < 2.00 significant congestion
• TTI > 2.00 severe congestion
These ranges of travel time indices were used to correlate to Low,
Medium, and High congestion needs for both vehicular and freight
congestion.
B2: Freight Congestion
Freight mobility is a significant consideration for the state’s
economy and industry. Therefore, it is recommended that freight
mobility be considered like the mobility analysis described above.
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