Average speed estimation in Fortaleza: comparison between enforcement radars and the Google Distance Matrix API

Authors

DOI:

https://doi.org/10.58922/transportes.v34.e3166

Keywords:

Mean speed estimation, Traffic level of service, Traffic planning and operations.

Abstract

Urban traffic management relies on reliable travel time data. Big data sources, such as commercial APIs, are low-cost alternatives to physical sensors, but the discrepancies between them need to be better understood, especially in developing countries. This paper performs a paired comparative analysis between average speed estimates from Google’s Distance Matrix API and those from enforcement radar (FE) sensors. The study covered 47 urban sections in Fortaleza, during the morning peak period over 69 weekdays. The results reveal a strong correlation (r > 0.93) for samples with at least 25 vehicles captured in 15 minutes, validating the API under higher flow conditions. However, a speed-dependent bias was identified: the API tends to overestimate speeds by up to +4.0 km/h in slow traffic and underestimate them by up to −6.5 km/h at higher speeds. For the most frequent speeds (10–40 km/h), the differences remained within a narrower range of −3.1 to +2.4 km/h.

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Author Biography

Manoel Mendonça de Castro Neto, Universidade Federal do Ceará

Possui graduação em Engenharia Civil pela Universidade Federal do Ceará (UFC). Fez mestrado em Engenharia de Transportes, mestrado em Estatística e doutorado Engenharia de Transportes na University of Tennessee, EUA. É professor associado do Departamento de Engenharia de Transportes da UFC e docente permanente do Programa de Pós-Graduação em Engenharia de Transportes, PETRAN/UFC, onde orienta discentes de mestrado e de doutorado. Atua na área de Engenharia Transportes, com ênfase em Engenharia de Tráfego, mais especificamente na modelagem multimodal do tráfego de vias urbanas.

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Published

2026-09-15

How to Cite

Machado de Araújo, M. A. and Mendonça de Castro Neto, M. (2026) “Average speed estimation in Fortaleza: comparison between enforcement radars and the Google Distance Matrix API”, Transportes, 34, p. e3166. doi: 10.58922/transportes.v34.e3166.

Issue

Vol. 34 (2026)

Section

Articles

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Copyright (c) 2026 Marco Antonio Machado de Araújo, Manoel Mendonça de Castro Neto

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Last update: 11/27/2025