Nationwide, United States
A Comprehensive Assessment of Highway Inventory Data Collection Methods
Summary Information
This study presented the results of a national survey conducted to evaluate the following state DOT infrastructure inventory data collection techniques:
Aerial/Satellite Imagery - High resolution images are taken from aircraft or satellite to identify and extract highway inventory information.
Field Inventory - GPS survey equipment and conventional optical are sued to collect desired information in the field.
Photo/Video Log - Instrumented vehicles automatically record photo/video data that can be examined later to extract information.
Integrated GPS/GIS Mapping - An integrated GPS/GIS field data logger is used to record and store inventory information.
Mobile LiDAR - Instrumented vehicles collect 3-D precision point information using LiDAR systems traveling at highway speeds.
Airborne LiDAR - Instrumented aircraft collect 3-D precision point information using LiDAR systems to derive highway inventory data.
METHODOLOGY
Survey respondents were requested to indicate their level of satisfaction with their primary collection method using a scale of 1 to 5 (representing unacceptable, fair, good, very good, and excellent, respectively) where one is worst and five is the best with regard to cost, time, accuracy, safety, and data storage requirements.
The satisfaction indicators considered in the survey included equipment cost, data accuracy, data completeness, crew hazard exposure, data collection cost, data collection time, data reduction cost, data reduction time, and data storage requirement.
FINDINGS
Findings were based on data collected from 30 respondent state DOTs. More than 50 percent of responding states use field inventory, integrated GPS/GIS mapping, video log, and aerial imagery for collecting roadside feature data. Satisfaction levels with their primary data collection method are shown below.
| Satisfaction Factors |
Satellite Imagery |
Photo log |
Aerial Imagery |
Field Inventory |
Video log |
Integrated GPS/GIS Map |
Mobile LiDAR |
Airborne LiDAR |
| Equipment Cost |
3.1 |
3 |
3.1 |
3.1 |
3.1 |
2.9 |
2 |
2.5 |
| Data Accuracy |
3.3 |
3.5 |
3.6 |
3.5 |
3.4 |
3.8 |
3 |
3 |
| Data Completeness |
3.2 |
3.3 |
3.3 |
3.4 |
3.3 |
3.3 |
3.4 |
2.8 |
| Crew Hazard Exposure |
3.2 |
3.4 |
2.9 |
2.9 |
2.9 |
3 |
2.5 |
3 |
| Data Collection Cost |
3.2 |
2.9 |
3 |
2.8 |
3 |
2.8 |
2.5 |
2.5 |
| Data Collection Time |
3.2 |
2.8 |
2.9 |
2.8 |
2.8 |
2.7 |
2.6 |
2 |
| Data Reduction Time |
2.8 |
3.1 |
2.9 |
3.1 |
2.8 |
2.9 |
2 |
2 |
| Data Reduction Cost |
3.2 |
3.1 |
2.9 |
2.7 |
2.8 |
2.8 |
2.5 |
2 |
| Data Storage Requirement |
3.2 |
3.5 |
3.4 |
3.3 |
3.1 |
3.3 |
3 |
3.4 |
