We developed and implemented a traffic survey system for statistical purposes for Paraguay’s national roads. The system is composed of three types of operating stations:

• 9 permanent positions: Operate 24 hours, year-round, for classified counting and weigh-in-motion (WIM). They are located in the primary network and communicate by modem.
• 14 seasonal stations: Operate 24 hours a day for 4 weeks a year for classified counts in the rest of the primary and secondary network.
• 75 coverage posts: Operate 24 hours per week each, for specific studies or to cover areas not monitored by the other posts.

The project included the supply, installation, maintenance and operation of the equipment for a period of six months. For the permanent and seasonal posts, we used piezoelectric sensors and magnetic coils. For the cover stations, we used pneumatic equipment.

We also process the information collected. For this purpose, we designed and programmed software that allows the entry, storage and processing of the data. This information allowed us to build a complete database with:

• Classified daily volumes (monthly and annual).
• Seasonal variation of volumes (hourly, daily and monthly).
• Characteristic speeds and lengths.
• Gross and axle weights of heavy vehicles and their equivalence to 18 kips axles.
• Annual growth trends by vehicle type.

Project impact

The Road Planning Directorate now has a complete traffic database for statistical analysis. This information is essential for project planning, economic evaluation and pavement design.