Overview

This award winning project brought survey-grade mobile lidar to a highly travelled section of I35W in northeast Minneapolis from Dinkytown to Cleveland Ave (Rosedale Center). The technology was needed to safely and quickly collect high accuracy surface information and bridge clearances for pending roadway resurfacing.

The Continental Mapping team employed survey-grade mobile lidar and imagery to ensure data collection didn’t impact traffic flow.

Field survey proved a challenge given that personnel could only be onsite between the hours of 9pm and 6am. This made the survey leveling phase of this project difficult. In order to complete the leveling phase of the project during the night, the team utilized illuminated survey levels. The survey proved to be highly accurate – exceeding project requirements. While surveyors ran levels through the night, the mobile lidar unit operated during the day running roadway lanes. The survey grade lidar was post-processed and developed into an initial surface.  Accuracies were confirmed at 0.05′ @ 1 sigma.

From the lidar’s preliminary surface, Continental Mapping’s technicians developed breaklines along the edge of pavement, the crown and all paint lines. After integrating these breaklines into the digital terrain model, an enhanced surface was developed. The data then progressed through numerous quality checks until it was ready for delivery.

Continental Mapping also provided what has become a favorite of our clients – The Continental Mapping Map Book – with each bridge highlighted on a page including an aerial shot, street level imagery from the mobile lidar and various point cloud captures with clearances identified.  Two PDF examples are provided below.

Project

I-35 Resurfacing and Clearances in Minneapolis

Client

Minnesota Department of Transportation

Lidar point cloud visualizing railroad tracks and trains with trees in the background in Minneapolis, Minnesota.
Three Continental Mapping staff (including CEO Dave Hart) holding plaques and accepting the ACEC-MN award for the resurfacing project.

CEO Dave Hart (center) accepts ACEC-Minnesota Award for Continental Mapping’s work on the resurfacing project.

An example of a Map Book showing an aerial image of bridge location, a street level view of bridge, and a virtual clearance measurement graphic of bridge.
An example of a Map Book showing an aerial image of bridge location, a street level view of bridge, and a virtual clearance measurement graphic of bridge.