Tag Archives: heavy vehicles

MnDOT Explores the Use of a Unified Permitting Process for Oversize/Overweight Loads

Researchers produced a proof-of-concept for developing a one-stop permitting process that would allow commercial haulers to plan a travel route and secure all required permits from a single source. MnDOT is working to develop a first-of-its-kind, unified permitting process to consolidate the requirements of every jurisdiction in the state into a single, quick-response platform that meets the needs of haulers.

“From a hauler’s perspective, the permitting process can be very cumbersome. Each agency’s application is different as are the general provisions that haulers need to follow,” said Renae Kuehl, Senior Associate, SRF Consulting Group, Inc.

“As carriers, we’re trying to do our due diligence in getting permits. But the current process can lead to significant safety and legal risks,” said Richard Johnson, Transportation Manager, Tiller Corporation.

What Was the Need?

Hauling oversize or overweight freight on Minnesota’s roadway system—highways, county roads, township roads and city streets—requires approval by each governing authority along the route. Roadway managers must review hauler travel plans to make sure size and weight limits for vehicles and loads will not endanger roadway facilities, hauler equipment and personnel before issuing the over-size or overweight permit.

Any single hauling route may require permits from multiple roadway authorities, each with different application procedures and response times. Some governing bodies, MnDOT among them, issue these permits online and can turn them around in minutes. Other agencies issue permits by mail, fax or email, which can take several days.

Haulers, however, may not have time to wait for a permit. If equipment breaks down at a loading site, for example, replacement equipment is needed immediately to meet contract deadlines and avoid paying labor costs for idle workers. A construction emergency may also demand large equipment be towed to a site. In situations like these, haulers often make the trip without appropriate permitting, accepting the legal and safety risks.

What Was Our Goal?

To simplify the permitting process, Minnesota local agencies would like to develop an online permitting application process that would allow permit-seekers to determine routes based on their vehicle and load size, and secure all necessary permits at one time. This research, the first phase of a multiphase study, aimed to determine the feasibility of a one-stop, unified permitting process by studying its technological and operational needs and gathering input from various stakeholders.

What Did We Do?

Investigators worked with the Technical Advisory Panel (TAP) and a group of policy experts from county and state agencies, commercial haulers and consultants to identify audiences with a stake in a unified permitting process. During meetings in northern Minnesota and in the Twin Cities area, investigators and TAP members met with key stakeholders: haulers and representatives from industry organizations; seven MnDOT offices (including Freight and Commercial Vehicle Operations, Information Technology, Maintenance and Geospatial Information); Minnesota counties; the City of Duluth; the Duluth-Superior Metropolitan Interstate Council; Minnesota State Patrol; the State Patrol Commercial Vehicle Section; and a county sheriff’s office.

The research team identified the challenges and needs of each stakeholder and organized the concerns according to policy, process and technology. Then they explored solutions that would allow the development of a one-stop permitting process.

What Did We Learn?

Researchers determined that a unified permitting process is feasible. Policy issues include the need to standardize general provisions statewide, such as travel hours, insurance requirements and warning devices such as flagging needs. For example, currently the color of flags and lettering on banners vary from jurisdiction to jurisdiction; well-framed general provisions could make these requirements more uniform to serve multiple jurisdictions. The information required by each governing authority in its permit applications could also be normalized.

Process issues were about workflow. More than 80 percent of hauler requests are repeat-able: A commercial haul may be run on the same route with the same-size load three times a month for four months and may not require a full reapplication each time. Some agencies rely on paper, fax or emails to receive permit requests; others purchase permit-ting software; still others build their own software. These systems could be made more uniform so they could interact and share information among agencies.

Technology issues called for an interoperable system that could bring together geographic information system (GIS) capabilities and regulatory data that could be both received and shared. Mapping data could identify each permit required along a route being developed, and a portal could allow agencies to share information as well as allow permit-seekers to enter information and retrieve permits themselves. A portal could also integrate different software packages while offering information like Minnesota’s Gopher State One Call digging hotline.

What’s Next?

In Phase II of this project, which has already begun, researchers will develop a pilot portal that allows users to create route plans, identify permits needed and apply for all permits in one action. Investigators will test the platform with a three-county group. If this effort is successful, researchers will build a unified permitting process for use within all jurisdictions in Minnesota.

MnDOT is also enhancing its software for handling oversize/overweight permits and carrier credentials. Transportation Research Synthesis 1704 surveyed state agencies about current offerings.


This post pertains to the LRRB-produced Report 2017-26, “Oversize/Overweight Vehicle Unified Permitting Process (UPP) Phase I,” published August 2017. 

Gauging safety of heavy vehicles on older concrete bridges

Bridges built using prestressed concrete girders are among the most common in Minnesota and throughout the U.S. because of their good performance, lower initial material costs, and relatively low ongoing maintenance costs. However, the federal requirements for these bridges have changed considerably over the years. As a result, bridges built to older specifications may score poorly when subjected to new bridge rating standards even though they are actually in good condition.

“One area in which this discrepancy between ratings and reality can cause problems is determining safe legal load limits for bridges, which are used to decide whether larger trucks may cross the bridge with an overload permit,” says Catherine French, CSE Distinguished Professor in the Department of Civil, Environmental, and Geo- Engineering and the study’s principal investigator.

“Our goal was to evaluate whether the current guidelines regarding shear forces (which transfer the loads to the supports) may be overly conservative for these older concrete bridges that are in good condition.”

Sponsored by MnDOT, the study was conducted by a team of U of M researchers including Carol Shield (co-investigator) and Benjamin Dymond.

Researchers used a multipronged approach consisting of numerical modeling and tests in both the laboratory and the field. The numerical modeling was used to apply the results of the laboratory and field tests to a study examining the effects of key parameters on the distribution of shear in a bridge system. Parameters included span length, girder spacing and depth, deck thickness, and load position.

Results showed that the shear forces for some bridges are not as high as those predicted by distribution factors in the current specifications—at least partially explaining why some MnDOT bridges with low shear ratings show no signs of distress, French says. The researchers provided recommendations for more refined methods of evaluating prestressed concrete girder bridges that rate low for shear and developed a screening tool to identify which bridges that rate low for shear should be further analyzed.

“The results of this project will help us re-evaluate aging bridges in our inventory, to distinguish those that really do have shear problems from those that don’t, and make decisions about whether they need to be replaced or rehabilitated for extra capacity,” says Yihong Gao, bridge designer with MnDOT’s Office of Bridges and Structures.

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