RoadMap™ Sensors
RoadMap Sensors measure the surface of asphalt and concrete roads, profile road smoothness and calculate roughness. Detailed information about RoadMap Sensors is coming soon. You can read a product overview below.
Specialty Sensors are purchased separately. They are not available through our online store.
Download RoadMap™ Data Sheet (Updated 12-2-09)
(Right-click to download. PDF file is 1.8MB. Need Adobe® Reader? Get it free here.)
To place an order or to learn more about RoadMap, please contact:
Michael Snow
Product Manager
Bytewise Measurement Systems
Phone (678) 807-8400
Contact (Please include RoadMap in the Comment section)
RoadMap™ Laser Profile Sensor Measures Road Roughness
The RoadMap-100™ is designed exclusively to measure the surface of asphalt & concrete roads, profile road smoothness and calculate roughness.
The RoadMap-100 is the latest line-based 6kHz, high speed laser profile sensor from Bytewise Measurement Systems. The RoadMap™ can be mounted on Light Weight and High Speed Profilers so State DOT’s and Paving Contractors score IRI (International Roughness Index) correctly.
Profile Lasers Offer More
Everyone enjoys driving on smooth roads. When roads are built, resurfaced and maintained, ride quality and the condition of the pavement surface are measured with laser sensors. Traditionally single point lasers have been used, but new generation laser line profile sensors are now state of the art. North America uses profile sensors to calculate IRI. The IRI index offers reliability and comparability to gather national road profile statistics. Paving Contractors are graded on smoothness. They can be issued bonuses or assessed penalties based on the final IRI valuation. Further studies show that smooth roads can increase gas mileage by 4.5%, reduce traffic noise, cause fewer accidents, and reduce maintenance cost while increasing long term sustainability.
The RoadMap-100™ accurately measures road smoothness which is reported in inches/mile (meters/kilometer) and defined by ASTM E867 specification. The IRI describes the sample method, and clarifies how the profile data is filtered. The index then explains how the data is reduced to a single cumulative number and converted to an appropriate scale. The IRI and ASTM specification are critical to collect, organize, consolidate, and report the data in a meaningful way to State DOT’s and the National Highway Administration. Several websites provide more information:
- ASTM – www.astm.org
- Transportation Research Board – www.trb.org
- AASTO – www.transportation.org
Verify IRI Correctly
The RoadMap™ sensor is mounted in front of each wheel path on a profiler vehicle that drives down the road at highway speeds. Each sensor collects 512 tracks of the highway surface profile at 6kHz, (512 tracks every 5mm distance traveled). The 512 points are spaced 0.195mm apart over a 100mm wide laser line to precisely measure the macro-granular texture of the road surface.
The increased volume of data is proven to better calculate and score IRI correctly as it simulates the width of a tire tread riding on the road surface. When filtered to a single value, matching the IRI; the road smoothness is generally reduced by 20 in./mile. IRI is reduced because coarse macro-granular texture effects on asphalt or tined concrete can falsely report poor IRI calculations when measured with single point laser (SPL) triangulation sensor. Most commonly used SPL’s measure into every crack, crevice or hole in the pavement. The tire tread generally rides over these features, masking the negative features; basically the vehicle and passengers are not affected.
The integrators of the road profilers are now using laser line profile sensors like the RoadMap™ to filter or bridge over these features and properly represent the true smoothness of the road.
The RoadMap™ System
This advanced technology is compact with sensor dimension of 127L x 120W x 88H (mm). Depth accuracy is +/- 0.100mm. The power requirement is 24VDC @ 250mW max. The RoadMap™ accepts a direct quadrature encoder input or pulse train, so distance traveled longitudinally down the road is tagged to each of the 512 X/Y data profiles. Communication output is a high speed Ethernet UDP protocol while the sensor and connectors are designed for harsh environments.
The Bytewise RoadMap™ sensor connects to a controller that allows easy integration and offers multiple communication protocols like; UDP Ethernet protocol, RS-422, High Speed Serial Communications and 0-20mA analog output. Users can select the numbers of tracks and turn on/off filtering and bridging algorithms used for longitudinal tined concrete.
