# Comparative Accuracy Analysis of Truck Weight Measurement Techniques
## 1 Introduction
This system can recognize the characters on vehicle license plates and analyze them, along with the gross vehicle weight (GVW), axle weight, and vehicle class obtained from the traditional sensors. The bridge weigh-in-motion system (B-WIM) is another measurement technique based on instrumenting a bridge and treating it as a large scale that measures vehicles' attributes. Typically, sensors measure strain in structural components, and dedicated software calculates the axle weights and axle spacings using influence lines/surfaces and calibration factors. B-WIM system is used as a weighing scale to monitor the axle weights of the vehicles passing through the bridge. The initial work relating to the B-WIM system was carried out in the US. In 1979 [PERSON] [5] published an article with a methodology based on bridge strain history analysis to estimate vehicle axle weight. In Australia, [PERSON] [6] developed and proposed the AXWAY system to determine vehicle axle load and GVW. In Europe, research in the field of WIM techniques started in the 1990s under the COST 323 program and later the WAVE (Weighing-in-motion of Axles and Vehicles for Europe) [7] project, which supported the B-WIM research development [8]. Those studies were used to create a commercially available B-WIM system. Nowadays, the system is widely used in Europe [1,9]. B-WIM systems are non-invasive and non-destructive techniques for traffic measurement that are based on monitoring strains in the bridge superstructure induced by vehicles passing over a structure. Measurements are usually conducted with strain gauges and strain transducers. The measured strains are converted into axle weights based on the selected algorithm [10]. The first algorithm [5] using bridge influence lines was improved and supplemented by [11]; the comparative analysis of algorithms in B-WIM is described in [12]. B-WIM systems are available in the literature [11,13,14]. The advantage of the B-WIM system is the reduction of the dynamic effects due to the fact that the bridge deck is used as a large weighing scale [2]. The accuracy of the measurement depends on the bridge deck condition and surface smoothness, which may induce excessive bridge vibration. The B-WIM installation and equipment itself do not affect the structure of the bridge. Furthermore, the B-WIM system also informs about traffic and provides a realistic response of the structure. There are numerous WIM stations all over the world, collecting millions of records with truck data every day. Many researchers have utilized the traffic data collected by WIMsystems for efficient bridge design and evaluation. The truck traffic volume, axle weights, and vehicle configurations have changed during recent decades, and systematic traffic data collection and evaluation provides a rational basis to update the design and evaluation provisions for bridges. The traffic varies from site to site, hence, the WIM data can serve as a source to modify the live load factor for site-specific traffic. AASHTO LRFD provides the protocols to update the live load factor for local traffic. The AASHTO provisions are based on a set of protocols developed by [PERSON] [15]. The truck traffic data was collected at different WIM sites around the US, and a reliability-based procedure was designed to determine the site-specific load factors. The method involves a list of requirements for WIM collection, quality, and quantity. Traffic data can also be used to identify overloaded vehicles in order to assess their effect on infrastructure. Some studies have used WIM data to capture overloaded vehicles in the traffic flow [16]. The overloaded vehicle evaluation may be essential in bridge posting decisions, and overloaded permit vehicles crossing the bridge can significantly contribute to the damage. Hence, permit vehicles' short-term and long-term effect was studied to assess their impact [17]. An increasing number of special permit vehicles, due to the escalated freight demand, can induce fatigue damage and reduce the bride load-carrying capacity.