Information about the travel forecasting package, Quick Response System II
I am on an NCHRP panel that is supervising a project to quantify the benefits of various methodologies for statewide travel forecasting. That project is getting close to finishing, so I wanted to compare our consultant’s findings to whatever may have come out of the recent NCHRP project to create the software tool, TFGuide web …
With much help and encouragement from Kermit Wies and TRB’s ADB45 committee, I have placed most of the content of the Hawaii Guidelines for project-level traffic forecasting on the TFResource.org website in fully editable format. At this moment there are 50 “topics” pages containing just about all the methodologies from the Hawaii Guidelines. Some longer …
Checking some citations within a draft report that I have been reading led me to pervasive alternative facts about the relationship between greenhouse gas emissions and traffic improvement strategies. It seems that not only are we daily subjected to incorrect interpretations about the sources of global warming, but we are additionally subjected to incorrect ideas …
Last week the 7th US Circuit Court of Appeals dealt a likely lethal blow to WisDOT’s plans to expand a long section of Wisconsin Highway 23 from two lanes to four lanes. The ostensible reason for the negative ruling was WisDOTs failure to use a consistent methodology for preparing its traffic forecasts. But the real …
Kermit Wies, at the 2016 Innovations in Travel Modeling Conference, gave a plenary speech that was honest, soul-bearing, and depressing. He was lamenting about the inaccuracies of travel models and his inability to defend them. Kermit is not alone. Many travel modelers have experienced this sinking feeling that their model might be spewing out seriously …
Truth be told, I volunteered to be a Foresight Ambassador for NCHRP. My and the several other ambassadors’ mission was to spread the word about NCHRP Foresight Reports 750. This series of six reports, as you have probably heard, develops future scenarios for transportation development and planning. All rookie ambassadors were supplied with a one-day …
After a recent presentation to the North Carolina Model Users Group about node delays in travel forecasting networks, I was asked how one knows where traffic signals should be on future-year networks. This is a complicated question, and my answer was sketchy and not particularly satisfying. I alluded to two papers I wrote on the …
If you were to assume that drivers are sensitive to the degree of reliability in travel time when they choose paths and if you wanted to include this sensitivity in your travel models, you would need a way to calculate path impedance from link impedance. You would also want a measure of variability (the inverse …
QRS II had always had a form of feedback to trip distribution (more correctly to trip generation, although the trip generation step was insensitive to network travel times). In 1988 or so when I was testing a new installation of a “modified” Evans’ algorithm I had put into QRS II, which was quite similar to …
It is not so much that the recent report for FTA “Traffic Assignment and Feedback” is wrong. (I will call it the TAF report from here on.) The TAF report is just not sufficiently prescriptive. It is absolutely clear from the TAF report that traffic assignments, as practiced by many large MPOs, are ill; but …