O-D studies are often used to determine cut-through routes and rush hour alternatives, which require a high capture rate for complete data. Travel time studies don’t usually require quite as high a capture rate, because vehicles on the same road at the same time are usually pretty close in speed and travel time between points.
Our associates spend time and resources researching the technologies for these studies. Currently, we have invested heavily in License Plate Recognition cameras, as these have the highest capture rate. We have completed O-D studies with as many as 67 Miovision ALPR cameras (http://miovision.com/blog/awesome-alpr-applications/) working simultaneously. We are also watching Bluetooth and cellular phone triangulation technologies as their capture rates improve every year.