The average annual daily traffic AADT as of 2011 was 121220 including 14187

The average annual daily traffic aadt as of 2011 was

This preview shows page 24 - 28 out of 71 pages.

the Missouri River. The average annual daily traffic (AADT) as of 2011 was 121,220 including 14,187 commercial trucks (11.7% of the AADT). The original speed limit of 60 mph was reduced to 45 mph within the work zone. Each of the four site characteristics warranting ITS deployment was met: congestion is frequent at the location, the duration of the work zone resulted in consistent delays and potential for crashes, alternative routes are available, and the demand is frequently at or above road capacity. Figure 3 shows the I-70 network with DMS and locations for traffic sensors.
Image of page 24
9 Figure 3. I-70 Blanchette Bridge work zone network map ITS was used at the Blanchette Bridge work zone site to promote traffic diversion during congested periods, warn drivers of lane closures, narrow lanes and reduced speed limits, and provide travel times. DMS was the main component of ITS used to provide en-route information to drivers while the pre-trip information was provided using newspaper, radio, television, and traveler information websites. Data Collection for I-70 Case Study Existing traffic sensors in the study area provided traffic data on the main roadways only (I-70, Rt. 364, and Rt. 370). They did not provide data on ramps. Ramp flows were necessary to obtain the diversion rates. Thus, ramp flows at several key decision points in the area was collected using portable video cameras deployed at the locations. A map of the data collection locations is shown in Figure 4 as red circles. Cameras were deployed strategically to capture the diversion volumes to each alternative route. Video data was collected during AM peak (7:00- 9:00), PM off-peak (1:00 2:00), and PM peak (4:00 6:00). Two datasets were collected: before data without work zone and during work zone data. The before and during work zone data were both collected on the same day of the week on a Wednesday. Traffic studies are usually conducted between Tuesday and Thursday because they represent the typical work day traffic. The before data was collected on October 24, 2012 and the during data on November 7, 2012.
Image of page 25
10 Portable video cameras were placed at six freeway interchanges: I-70/Rt. 370, I-70/Rt. 94, I- 70/Earth City Expressway heading westbound, I-70/I-270, I-270/Rt. 370, and I-270/Rt. 364. By comparing the before and during work zone flows, the work zone induced diversion rates were calculated. They were 9.2% during AM peak, 1.9% during off-peak, and 9.2% during PM peak. Figure 4. I-70 network map showing the data collection locations
Image of page 26
11 Figure 5 shows the diversion towards each detour route and time periods recorded for the AM peak hours (blue arrows), pm peak hours (black arrows), and an off-peak hour in the afternoon (red arrow). Table 3 shows the percentage of mainline traffic accessing each alternative route before and during the work zone. The diversion rate is then calculated by subtracting the before and during percentages and is reported in the final column of Table 3.
Image of page 27
Image of page 28

You've reached the end of your free preview.

Want to read all 71 pages?

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors