ITS Heartland 2012 Annual Meeting Kansas City, MO Please visit our Vimeo site to access voice narrated presentations: https://vimeo.com/matc/review/42287726/53219965ee Presented by Yifeng Chen, Graduate Research Assistant, Nebraska Transportation Center and Zheng Luo, Graduate Research Assistant,Nebraska Transportation Center

1. Traffic Analysis and
Improvements for the
‘Legends’ Development Area
by Yifeng Chen, Ph.D. Cand.
Zheng Luo, Ph.D. Cand.
ITS Heartland’s 2012 Annual Meeting
March 26 -28 2012

2. Study Area
Study Area I-435
‘Legends’
Development
Parallel Pkwy
Area
State Ave
Kansas
City
I-70
K-7

3. Selection of Study Segments
Study Area I-435
‘Legends’
Development A
Parallel
Area Pkwy
C State Ave
D E
I-70
B
K-7
Direction of Traffic on
a Roadway Segment

4. Study Objective
Evaluation of current traffic situation with
respect to traffic speeds and travel times in
2009 and 2011, to see if there are any
changes
Evaluation of impact of NASCAR race event
traffic on the study area

5. Data Processing
INRIX Archive speed data in Speed distributions
5 min aggregation (24h): 2009 vs. 2011
from May01 – July02, 2009 (mean, median, max,
from May 01 – July 02, 2011 Five segments min etc.)
INRIX Archive speed data in 5
min aggregation (24h):
Sun, June 05, 2011 NASCAR Hourly travel time:
race day race day vs. normal
Sun, June 12,2011 normal day day
Four segments
Average travel time in 1h
aggregation (24h) Hourly travel time
Sun, June 05, 2011 NASCAR Four segments
reliability:
race day race day vs. normal
Sun, June 12,2011 normal day day

6. Sun, June 05, 2011 NASCAR race day!

7. Segment Speed Distributions (5 mins)

8. Segment Speed Distributions (5 mins)
Speed Limit
Segment A,B
Speed Limit
Segment D
Speed Limit
Segment C,E
T test: p<0.01 T test: p<0.01 T test: p<0.01 T test: p<0.01 T test: p<0.01
2009<2011 2009>2011 2009<2011 2009>2011 2009<2011
Null Hypothesis: mean speed in 2009=mean speed in 2011

9. Segment Speed Distributions (5 mins)
Speed Limit
Segment A,B
Speed Limit
Segment D
Speed Limit
Segment C,E
T test: p<0.01 T test: p<0.01 T test: p<0.02 T test: p<0.01 T test: p<0.01
2009<2011 2009>2011 2009<2011 2009>2011 2009<2011
Null Hypothesis: mean speed in 2009=mean speed in 2011

10. Segment Travel Time
NAS NAS
CAR CAR
race race
1pm 1pm
- -
4pm 4pm
NAS
NAS
CAR
CAR
race
race
1pm
Gap
1pm
-
-
4pm
4pm

11. Travel Time Reliability
 Different definitions from different viewpoints
 Simple Definition: How do travel times vary for a
certain time interval
 90th or 95th percentile travel times, buffer index and
planning time index
 Buffer Index= (95 % TT- meanTT)/mean TT
• Route Specific: A measure of how much more time in
percentage a traveler should prepare in advance to
ensure on-time arrival, with respect to the mean travel
time
• Segment specific: The amount of extra time a driver
should plan for traversing the segment

12. Segment Buffer Index Values
NAS
NAS
CAR
CAR
race
race
1pm
1pm
-
-
4pm
4pm
Valley Peak
NAS NAS
CAR CAR
race Gap
race
1pm 1pm
- -
4pm 4pm

13. Conclusions
 Statistically significant difference in speed distributions
on 5 studied segments between 2009 and 2011
 Operation speeds close to speed limits
 Sufficient capacity for current traffic demand on both
race days and normal days based on limited study of 5
segments
 Event traffic has increased on both mean and buffer
travel times for the Outbound State Ave.
 Travel time reliability (e.g. Buffer index) is a more
informative parameter for the impact of event traffic
than mean travel time

14. Recommendations
 Future research: more comprehensive study
• Average buffer index values on different segments/routes
for the same time interval
• Buffer index on the same segments/routes in 2009 and
2011
• Use other parameters: 95% travel time, planning time index
 Advance Traveler Information System for ‘Legends’
Development Area
 For Travelers: Mean Travel time, Range of Travel time,
Reliable Routes for peak hours or race days

15. Thank you!
Questions?
Slide design © 2009, The Board of Regents of the University of Nebraska,
and Mid-America Transportation Center. All rights reserved.

17. Segment Travel Time Reliability
Peak
NAS NAS
CAR CAR
race race
1pm 1pm
- -
4pm 4pm
Valley
NAS NAS Gap
CAR CAR
race race
1pm 1pm
- -
4pm 4pm

18. Segment Travel Time
NAS NAS
CAR CAR
race race
1pm 1pm
- -
4pm 4pm
NAS NAS
CAR CAR
race race
1pm 1pm
- -
4pm 4pm