Crash Analysis Part 4 – St. Louis Park Case Study

Guest post by Jonah Finkelstein, EIT Spack Consulting Now that we have an understanding of the available Crash Analysis tools provided by MnDOT (see our previous posts here, here, and here), let’s look into a real-world example of the application of these tools in a corridor crash analysis. [Check out our Traffic Corner Tuesday – Crash […]

Median Acceleration Lanes a Mixed Bag

Guest Post by Max Moreland, PE, Director of Operations at Traffic Data Inc. Median Acceleration Lanes (MALs) are just what they sound like – an acceleration lane on the inside median. MALs are intended to allow left turning vehicles from the side streets, or U-turning vehicles on the mainline, to complete their turn without needing […]

Removing a Left Turn Lane to Provide for a Bike Lane

Bicyclist. It is a word that can incite frustration in the minds of both drivers and traffic engineers alike. But, let’s face it: bicycles are good for the environment, they are cost-effective, they are good for our collective and individual health, and the presence of cyclists within a community creates a positive image that says […]

Case Study: Iterating an Event Traffic Study at a Buddhist Temple

This article was originally published in 2015, but has been updated with additional information. We would love to hear from our readers on their traffic study experiences for event traffic. Post your comment or write us at We were hired to conduct a “traffic study” for a minor expansion to a Buddhist Temple.  The […]

New HCM Methodology for Work Zone Alternatives

Applying Capacity Reductions to Account for the Effects of Work Zones

One of the more significant additions to the new 6th Edition of the Highway Capacity Manual (HCM) are equations to account for the effects of work zones.  Based on NCHRP Report 03-107, reduction factors have been developed to reduce capacity, free flow speed, and saturation flow rates in four of the analysis modules. Several state […]

Crash Analysis: Intersection Crash Rate

Guest post by Jonah Finkelstein, EIT Spack Consulting With the definitions discussed in Crash Analysis Definitions, we can now look into some of the tools provided by the Minnesota Department of Transportation (MnDOT) to help analyze crash rates around the state. This blog post will focus on MnDOT’s tool for intersection crashes known as the […]

4-Way Stop vs. Roundabout – MythBusters Experiment

MythBusters set up an experiment to determine which intersection works better – 4 Way Stop Signs or Roundabouts – check out the ten minute video below. Experiment Setup In a parking lot with barrels Single lane approaches at four legged intersection Show driver which way to go (left, through, right) as they pull up to the […]

How to Decide When You Need Micro-Simulation Analysis

Comments we often receive regarding our use of PTV Vistro in comparison to Synchro/SimTraffic are in regard to micro-simulation. Specifically, Synchro/SimTraffic is purchased as one software package while VISSIM, which is the SimTraffic equivalent for Synchro, is a separate software from PTV. In these situations, we need to step back and first determine whether a […]

HCM 6th Edition: Roundabout Calculation Changes

The 6th Edition of the Highway Capacity Manual (HCM) is out and we (and others) would characterize it as an update as opposed to an overhaul. While this new manual does contain new and interesting items, we’ll focus on roundabouts for this article. HCM2010 was ground-breaking in the U.S. for providing a new methodology to […]

PTV Vistro – Traffic Study Mitigation Made Easy

Guest Post by Bryant Ficek, PE, PTOE, Vice President at Spack Consulting. For many traffic studies, testing different improvement alternatives is a key element of the study. Things like turn lanes, different traffic control, adding/removing access, and many other options should be considered to improve traffic flow. With Vistro, we actually have two methods to test […]