{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T12:23:47Z","timestamp":1774268627522,"version":"3.50.1"},"reference-count":15,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2009,7,28]],"date-time":"2009-07-28T00:00:00Z","timestamp":1248739200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>School zones are areas near schools that have lower speed limits and where illegally parked vehicles pose a threat to school children by obstructing them from the view of drivers. However, these laws are regularly flouted. Thus, we propose a novel wireless sensor network application called School zone Safety System (S3) to help regulate the speed limit and to prevent illegal parking in school zones. S3 detects illegally parked vehicles, and warns the driver and records the license plate number. To reduce the traveling speed of vehicles in a school zone, S3 measures the speed of vehicles and displays the speed to the driver via an LED display, and also captures the image of the speeding vehicle with a speed camera. We developed a state machine based vehicle detection algorithm for S3. From extensive experiments in our testbeds and data from a real school zone, it is shown that the system can detect all kinds of vehicles, and has an accuracy of over 95% for speed measurement. We modeled the battery life time of a sensor node and validated the model with a downscaled measurement; we estimate the battery life time to be over 2 years. We have deployed S3 in 15 school zones in 2007, and we have demonstrated the robustness of S3 by operating them for over 1 year.<\/jats:p>","DOI":"10.3390\/s90805968","type":"journal-article","created":{"date-parts":[[2009,7,28]],"date-time":"2009-07-28T11:28:45Z","timestamp":1248780525000},"page":"5968-5988","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["S3: School Zone Safety System Based on Wireless Sensor Network"],"prefix":"10.3390","volume":"9","author":[{"given":"Seong-eun","family":"Yoo","sequence":"first","affiliation":[{"name":"Korea Advanced Institute of Science and Technology \/ Daejeon 305-701, Korea"}]},{"given":"Poh Kit","family":"Chong","sequence":"additional","affiliation":[{"name":"Korea Advanced Institute of Science and Technology \/ Daejeon 305-701, Korea"}]},{"given":"Daeyoung","family":"Kim","sequence":"additional","affiliation":[{"name":"Korea Advanced Institute of Science and Technology \/ Daejeon 305-701, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2009,7,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Sung, J., Ahn, S., Park, T., Jang, S., Yun, D., Kang, J., Yoo, S., Chong, P.K., and Kim, D. (2008, January March). Wireless Sensor Network for Cultural Property Protection. Okinawa, Japan.","DOI":"10.1109\/WAINA.2008.259"},{"key":"ref_2","unstructured":"Yoo, S., Kim, J., Kim, T., Ahn, S., Sung, J., and Kim, D. (2007, January June). A2S: Automated Agriculture System Based on WSN. Dallas, TX, USA."},{"key":"ref_3","unstructured":"Phan, T., Kwan, B.W., and Tung, L.J. (1997, January October). Magnetoresitors for Vehicle Detection and Identification. Orlando, FL, USA."},{"key":"ref_4","unstructured":"Kanian, A.N. (2000). [A Wireless Sensor Network for Smart Roadbeds and Intelligent Transportation Systems, MIT]. Master Thesis,."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"173","DOI":"10.1177\/0361198105191700119","article-title":"Traffic Measurement and Vehicle Classification with a Single Magnetic Sensor","volume":"1917","author":"Cheung","year":"2004","journal-title":"J. Trans. Res. Board"},{"key":"ref_6","unstructured":"Cheung, Y.S., Coleri, S., and Varaiya, P. (, January November). Traffic Surveillance with Wireless Magnetic Sensors. San Francisco, CA, USA."},{"key":"ref_7","unstructured":"Ding, J., Yiu, S., Tang, C., and Varaiya, P. (2004, January October). Signal Processing of Sensor Node Data for Vehicle Detection. Washington, DC, USA."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"920","DOI":"10.1109\/TMC.2006.100","article-title":"PEDAMACS: Power Efficient and Delay Aware Medium Access Protocol for Sensor Networks","volume":"5","author":"Coleri","year":"2006","journal-title":"IEEE Trans. Mob. Comput"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Yoo, S., Chong, P.K., Park, T., Kim, Y., Kim, D., Shin, C., Sung, K., and Kim, H. (2008, January March). DGS: Driving Guidance System Based on Wireless Sensor Network. Okinawa, Japan.","DOI":"10.1109\/WAINA.2008.184"},{"key":"ref_10","unstructured":"Ash, K.G. (2006). [Increasing Speed Limit Compliance in Reduced-speed School Zones, Brigham Young University]. MS thesis,."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"667","DOI":"10.1016\/S0001-4575(97)00036-5","article-title":"Vehicle Travel Speeds and the Incidence of Fatal Pedestrian Crashes","volume":"29","author":"Anderson","year":"1997","journal-title":"Accid. Anal. Prev"},{"key":"ref_12","unstructured":"(2006). Vehicle Detection Station Device White Paper, Wilbur Smith Associates\/IBI Group."},{"key":"ref_13","unstructured":"Sharafsaleh, A. (2006). Commercially-off-the-Shelf (COTS) and Emerging Technologies Sensor Testing and Evaluation, University Of California. California PATH Research Report, UCB-ITS-PRR-2006-15;."},{"key":"ref_14","unstructured":"Yoo, S., Chong, P.K., Kim, T., Kang, J., Kim, D., Shin, C., Sung, K., and Jang, B. (, January May). PGS: Parking Guidance System Based on Wireless Sensor Network. Santorini, Greece."},{"key":"ref_15","unstructured":"(2007). Accuracy Assessment of the Sensys Wireless Vehicle Detection System by Florida A&M University\/Florida State University, White Papers, Sensys Networks Inc."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/9\/8\/5968\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T22:10:50Z","timestamp":1760220650000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/9\/8\/5968"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2009,7,28]]},"references-count":15,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2009,8]]}},"alternative-id":["s90805968"],"URL":"https:\/\/doi.org\/10.3390\/s90805968","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2009,7,28]]}}}