Traffic Survey is a very small profile in the Infrastructure Industry, but indeed plays a vital role in deciding the success of an entire project.
All major Infrastructure projects starts with planning and traffic data is the main input for the planning process. This shows how important the traffic data is and its need for accuracy. There are different Data Collection Methods available and each has its advantages and limitations. Bad traffic data can have huge impact on the entire project. So the traffic consultants, planners and infrastructure firms should consider choosing a traffic survey agency based on its experience, exposure to various methods, international experience, quality certifications, etc rather than the cost.
There is a wide range of data collection methods that is followed worldwide for different types of surveys. A manual survey at site is the most common and traditional survey method. Because of its cost-effectiveness and the availability of data immediately after the survey, this method is a favourite among many. But this has serious quality limitations. Some of the surveys like Road Side Interviews, Market Research, Parking beats cannot avoid manual involvement at site. But it is recommended to have experienced enumerators/interviewers on site.
In the West, most of the manual surveys are now being filmed using HD cameras and then processed using experienced enumerators in a controlled office environment. With the videos, we are able to have a better control over the data quality. The accuracy is well over 95% in such video based surveys. But weather is an issue for videos. There are many Automatic Traffic Counters in the form of piezo electric, Pneumatic Tubes, Infra-Red, Radar and Bluetooth etc. These automatic counters provide reasonably high quality data and they have their own limitations. Most of these are used for Mid-Block counts and have limitations when it comes to intersection counts in Urban Planning. There is a recent advancement in the field of Video analytics. Even though this is still in primitive stages, this is expected to be the future. The ANPR (Automated Number Plate Recognition) is widely used for O-D surveys but these are currently very limited in India. The key factors for choosing one among the above methodologies are its ability, cost, accuracy and turn around times.
International Standards and Working Practices
The Traffic data collection industry in the West is governed by strict health and safety procedures and various quality standards. The agencies that have ISO certifications and that are accredited to health and safety assessment schemes have competitive edge. Similarly, we need to appreciate traffic survey companies that have ISO certifications to improve the overall data standards in the country.
Impact of bad data
Traffic data is fundamental to all transportation Infrastructure planning and improvements. Inaccurate traffic data can affect the entire Infrastructure project very badly. Inaccurate data can be either an undercount or an over count. Both have terrible impact on the entire project. We read stories about a toll collection firm that bid heavily on the basis of an over count data (bad data). It is struggling to break-even because of wrong projections. Similarly, an under count has resulted in huge queues at the toll plazas and they were eventually removed. The cost to rectify the errors is huge and it is worth spending reasonable budget for Accurate Data Collection.Madhu Meenakshi K,
Managing Director, DataCorp