By Bryant Ficek, PE, PTOE
A Traffic Impact Study (TIS) is a key product of traffic engineering, evaluating the impact of expected development traffic on the transportation network. For traffic engineers at both public agencies and private companies, there is always an underlying pressure to deliver a quality TIS faster while reducing the overall cost. Improvement in our evaluation tools is one method to achieve these seemingly conﬂicting goals.
For more than two decades Spack Consulting has been the recognized industry leaders of traffic studies, providing a best-in-class traffic analysis for government agencies, architects, developers and consulting engineering firms. A core part of Spack Consulting’s vision is to improve transportation globally through sharing our learnings with other transportation professionals.
This case study was developed to provide key learnings and insights the organization has realized through the comparison of traffic analysis software tools. This case study does not evaluate the software results, but rather the time necessary in successfully completing a TIS using each software. By tracking the time necessary for each in a real-world setting, readers can see the which software is the most appropriate tool for this function of traffic engineering.
Using the proper software will help you work smarter to improve your efficiency and, ultimately, provide an improved product to your client.
Case Study Summary
Two TIS projects were completed using both Vistro and Synchro Studio (Synchro) to analyze the study intersections. In both projects, Vistro took less time to complete the necessary work as compared to Synchro. In example project #1, Vistro saved four hours of project work or about ten percent of the overall project time. In example project #2, Vistro saved 11.5 hours or about 27 percent of the overall project time. Two key components lead to this time savings:
- Scenario Management. Vistro is designed to analyze multiple scenarios within one file, allowing for global changes in a base file to change all scenarios. It is also easily for someone to track scenarios with this file as compared to Synchro’s use of file data transfers or separately saved files for each scenario.
- Automated Graphics. Vistro includes standard graphics as part of its report generation, such as approach lane/traffic control and scenario traffic volumes. Synchro requires the use of a separate CAD software to prepare the exhibits. Pre-made graphics can reduce the time to develop them using Synchro, but still introduces potential issues associated with re-typing information or file transfers.
Spack Consulting realized improved efficiency using Vistro as compared to Synchro. Time savings result in faster completion of reports which translates into reduced project costs. The scenario management and automated graphics provide for increased quality by reducing potential errors through added data entry or file transfers. From the results of the two projects in this case study, the purchase price for Vistro can be recouped in time savings in four to ten standard TIS projects.
For Spack Consulting, the time savings from using Vistro has resulted in significant cost savings. Spack Consulting completes more than a 100-TIS projects each year. The time savings based on the average of the two projects in the case study, resulted in more than 775 hours of time savings. Assuming a $100 per hour rate, the direct cost savings is as much as $77,500 annually.
Want to see the actual study? Download it here.