Hao Xu
- Phone: (775) 784-6909
- Email: haox@unr.edu
- Building: SEM
- Room: 223
- Mailstop: 0258
Hao Xu’s recent research areas include roadside LiDAR sensing networks, algorithms for processing high-density city cloud points, edge- and cloud-based data processing, connected vehicle communication, all-traffic trajectory generation from roadside LiDAR data, GIS-based traffic information extraction from LiDAR trajectory data, automatic road feature extraction from mobile and arterial LiDAR and image data sources. His research group is a worldwide leader in roadside LiDAR sensing and applications in traffic.
Xu and his collaborators are applying roadside LiDAR technologies and all-traffic trajectory data to connected-autonomous vehicle applications, real-time traffic signal control systems, and performance evaluation of multimodal traffic safety and mobility. He has published over 100 research papers and his research team has received multiple research and paper awards.
Xu led the implementation of the world’s first LiDAR-equipped smart and connected intersection in Reno, Nevada, in 2017. Since then, he has performed innovative research in roadside LiDAR hardware, algorithms, software implementation, data applications, real-time signal systems taking LiDAR data input and LiDAR data service to CAVs. His research team implemented the world’s first LiDAR-controlled pedestrian crossing signal, which is the first real-time traffic signal system controlled by cloud point sensing data.
Based on Xu’s research and projects, the University and Velodyne Lidar technology company published a white paper demonstrating the ability of LiDAR sensors to make transportation infrastructure more efficient, sustainable and safe. Xu’s team collected multiyear roadside LiDAR data from various traffic scenarios and now maintains a large roadside LiDAR database as an invaluable data asset for smart traffic research.
Xu’s research has attracted collaboration interest from multiple companies such as Velodyne Lidar, Intel, Dell, Qualcomm and Switch. His research and projects have been noted by multiple media publications, such as BBC, USA Today, Yahoo News, Business Wire, AASHTO Journal and Nevada Today. Multiple traffic agencies have adopted the portable roadside LiDAR platform to collect extensive traffic information that is not available via traditional traffic sensors.
- Ph.D., Transportation Engineering, Texas Tech University, 2011
- M.S., Transportation Engineering, Texas Tech University, 2009
- M.E., Automation, University of Science and Technology of China, 2007
- B.E., Automation, University of Science and Technology of China, 2004
Prospective graduate students
Dr. Xu has research assistant scholarships for new Ph.D. students. The positions will be involved in the following research topics:
- Big data analysis of traffic crashes and intelligent transportation real-time sensor data
- Automatic traffic data survey system with videos and 360-degree LIDAR sensors
- Data analysis of latest driver behavior and vehicle sensor data from U.S. Federal Highway Administration
- Traffic crash prediction modeling
Research interests
- Collection and analysis of roadside LiDAR data
- Vehicle operation cost evaluation
- Driving behavior analysis with naturalistic driving study data
- Intelligent transportation systems including connected vehicles
- Data-driven traffic safety analysis
Grants received
- PI, Pilot Deployment of Roadside LiDAR in City of Henderson NV, Regional Transportation Commission of Southern Nevada, $86,071, 2018 - 2019
- PI, Proof-of-Concept Research of Roadside LiDAR Sensing Multimode Traffic, Nevada Department of Transportation, $313,397, 2018 - 2021
- PI, Pilot Applications of Roadside LiDAR Technologies in Washoe County, Regional Transportation Commission – Washoe County, $250,000, 2018 - 2020
- PI, Data Collection of Wildlife Animals Crossing I80 in Eastern Nevada and USA Parkway, SOLARIS UTC and Nevada Department of Transportation, $136,051, 2018-2019
- PI, Development of a Nevada wildlife-fencing GIS dataset, SOLARIS UTC and Nevada Department of Transportation, $145,817, 2018-2019
- PI, University of Nevada Support Services to NDOT Traffic Safety Engineering, Nevada Department of Transportation, $500,000, 2017-2022
Selected publications
- Shanglian Zhou, Hao Xu, Guohui Zhang, Tianwei Ma, and Yin Yang, 2024, DCOR: Dynamic Channel-Wise Outlier Removal to De-Noise LiDAR Data Corrupted by Snow, IEEE Transactions on Intelligent Transportation Systems, Print ISSN: 1524-9050, Online ISSN: 1558-0016, Digital Object Identifier: 10.1109/TITS.2023.3347150.
- Zhao, J., Xu, H., Chen, Z. and Liu, H., 2023. Accurate detection of vehicle, pedestrian, cyclist and wheelchair from roadside light detection and ranging sensors. Journal of Intelligent Transportation Systems, pp.1-17, DOI: 10.1080/15472450.2023.2243816.
- Chen, Z., Xu, H., Zhao, J. and Liu, H., 2023. A Novel Background Filtering Method with Automatic Parameter Adjustment for Real-Time Roadside LiDAR Sensing System. IEEE Transactions on Instrumentation and Measurement, 72, pp. 1-10, 2023, Art no. 5022310, doi: 10.1109/TIM.2023.3300457.
- Guan, F., Xu, H. and Tian, Y., 2023. Evaluation of Roadside LiDAR-Based and Vision-Based Multi-Model All-Traffic Trajectory Data. Sensors, 23(12), p.5377.
- Zhao, J., Xu, H., Chen, Z. and Liu, H., 2023. A decoding-based method for fast background filtering of roadside LiDAR data. Advanced Engineering Informatics, 57, p.102043.
- Zhou, S., Xu, H., Zhang, G., Ma, T. and Yang, Y., 2023. Deep learning-based pedestrian trajectory prediction and risk assessment at signalized intersections using trajectory data captured through roadside LiDAR. Journal of Intelligent Transportation Systems, pp.1-13.
- Zhang, Q., Bhattarai, N., Chen, , Xu, H. and Liu, H., 2023. Vehicle Trajectory Tracking Using Adaptive Kalman Filter from Roadside Lidar. Journal of Transportation Engineering, Part A: Systems, 149(6), p.04023043.
- Chen, Z., Xu, H., Zhao, J. and Liu, H., 2023. Curbside Parking Monitoring With Roadside LiDAR. Transportation Research Record, 2677(10), pp.824-838.,
- Bhattarai, N., Zhang, Y., Liu, H., Pakzad, Y. and Xu, H., 2023. Proactive Safety Analysis Using Roadside LiDAR Based Vehicle Trajectory Data: A Study of Rear-End Crashes. Transportation Research Record, p.03611981231182704.
- Cui, Y., Xu, H. and Gong, K., 2023. A diversion routing optimization model for urban evacuation planning. Natural Hazards, pp.1-18.
- Zhou, S., Xu, H., Zhang, G., Ma, T. and Yang, Y., 2022. Leveraging Deep Convolutional Neural Networks Pre-Trained on Autonomous Driving Data for Vehicle Detection From Roadside LiDAR Data. IEEE Transactions on Intelligent Transportation Systems. Volume: 23, Issue: 11, Page(s): 22367-22377.
- Zhang, Y., Bhattarai, N., Zhao, J., Liu, H. and Xu, H., An Unsupervised Clustering Method for Processing Roadside LiDAR Data with Improved Computational Efficiency. IEEE Sensors Journal.
- Cui, Y., Zou, F., Xu, H., Chen, Z. and Gong, K., 2022. A novel optimization-based method to develop representative driving cycles in various driving conditions. Energy, p.123455.
- Chen, Z., Xu, H., Zhao, J. and Liu, H., 2022. Fast-spherical-projection-based point cloud clustering algorithm. Transportation research record, 2676(6), pp.315-329.
- Zhao, J., Xu, H., Zhang, Y., Shankar, V. and Liu, H., 2022. Automatic Identification of Vehicle Partial Occlusion in Data Collected by Roadside LiDAR Sensors. Transportation Research Record, p.03611981211069347.
- Zhao, J., Xu, H., Tian, Y. and Liu, H., 2022. Towards application of light detection and ranging sensor to traffic detection: an investigation of its built-in features and installation techniques, Journal of Intelligent Transportation Systems, DOI: 10.1080/15472450.2020.1807346
- Whitley, T., Tian, Y. and Xu, H., Headway Data Extraction and Highway Capacity Manual Capacity Function Calibration for Roundabouts with Roadside Lidar Data. Transportation Research Record, p.03611981221132853.
- Zhao, J., Xu, H., Zhang, Y., Tian, Y. and Liu, H., 2021. Traffic Volume Detection Using Infrastructure-Based LiDAR under Different Levels of Service Conditions. Journal of Transportation Engineering, Part A: Systems, 147(11), p.04021080.
- Tian, Y., Xu, H., Guan, F., Toshniwal, S. and Tian, Y., 2021. Projection and integration of connected-infrastructure LiDAR sensing data in a global coordinate. Optics & Laser Technology, 144, p.107421.
- Cui, Y., Xu, H., Zou, F., Chen, Z. and Gong, K., 2021. Optimization Based Method to Develop Representative Driving Cycle for Real-World Fuel Consumption Estimation. Energy, p.121434.
- Wu, J., Xu, H., Yue, R., Tian, Z., Tian, Y. and Tian, Y., 2021. An automatic skateboarder detection method with roadside LiDAR data. Journal of Transportation Safety & Security, 13(3), pp.298-317.
- Wu, J., Xu, H., Sun, R. and Zhuang, P., 2021. Road Boundary-Enhanced Automatic Background Filtering for Roadside Lidar Sensors. IEEE Intelligent Transportation Systems Magazine, 14(4), pp.60-72.
- Wu, J., Xu, H., Tian, Y., Zhang, Y., Zhao, J. and Lv, B., 2020. An automatic lane identification method for the roadside light detection and ranging sensor. Journal of Intelligent Transportation Systems, pp.1-13.
- Wu, J., Xu, H., Tian, Y., Pi, R. and Yue R., 2020. Vehicle Detection under Adverse Weather from Roadside LiDAR Data, Sensors, 20(12), 3433; https://doi.org/10.3390/s20123433 (registering DOI)
- Zhang, Y., Yao, E., Zheng, K. and Xu, H., Metro passenger’s path choice model estimation with travel time correlations derived from smart card data. Transportation Planning and Technology, 43(2), pp.141-157.
- Wu, J., Zhang, Y. and Xu, H., A novel skateboarder-related near-crash identification method with roadside LiDAR data. Accident Analysis & Prevention, 137, p.105438.
- Zhang, Y., Xu, H. and Wu, J., 2020. An Automatic Background Filtering Method for Detection of Road Users in Heavy Traffics Using Roadside 3-D LiDAR Sensors With Noises, IEEE Sensors Journal, Volume:20, Issue:12, P. 6596-6604, ISSN: 1530-437X/1558-1748, Digital Object Identifier: 10.1109/JSEN.2020.2976663
- Yang, G., Wang, Z., Tian, Z., Zhao, L.Y. and Xu, H., Geometric design of metered on-ramps: State-of-the-practice and remaining challenges. Transportation Letters, 12(9), pp.649-658.
- Wu, J., Xu, H., Zhang, Y. and Sun, R., 2020. An Improved Vehicle-Pedestrian Near-Crash Identification Method with a Roadside LiDAR Sensor. Journal of Safety Research.
- Wu, J. Xu, H., Zhang, Y., Tian, Y. and Song, X., 2020. Real-time Queue Length Detection with Roadside LiDAR Data, Sensors 2020, 20(8), 2342.
- Cui, Y., Xu, H., Wu, J. and Wang, A., 2020. Lane Change Identification and Prediction with Roadside LiDAR Data, Optics and Laser Technology, DOI: 10.1016/j.optlastec.2019.105934.
- Wu, J. and Xu, 2020. Automatic Vehicle Detection with Roadside LiDAR Data under Rainy and Snowy Conditions, IEEE Intelligent Transportation Systems Magazine, accepted.
- Yue, R., Xu, H., Wu, J., Sun, R. and Yuan, C., 2019. Data registration with ground points for roadside LiDAR sensors. Remote Sensing, 11(11), p.1354.
- Zhang, Y., Sun, X., Xu, H., and Yao, E., 2019. Tracking Multi-Vehicles with Reference Points Switches at the Intersection Using a Roadside LiDAR Sensor, IEEE Access, ISSN: 2169-3536, 10.1109/ACCESS.2019.2953747, pp 1-11.
- Zhang, Z., Zheng, J., Xu, H., Wang, X., Fan, X. and Chen, R., 2019. Automatic Background Construction and Object Detection Based on Roadside LiDAR. IEEE Transactions on Intelligent Transportation Systems.
- Zhao, J., Li, Y., Xu, H. and Liu, H., 2019. Probabilistic Prediction of Pedestrian Crossing Intention Using Roadside LiDAR Data. IEEE Access, 7, pp.93781-93790.
- Lv, B., Xu, H., Wu, J., Tian, Y., Zhang, Y., Zheng, Y., Yuan, C. and Tian, S., 2019. LiDAR-enhanced connected infrastructures sensing and broadcasting high-resolution traffic information serving smart cities. IEEE Access, 7, pp.79895-79907.
- Cui, Y., Wu, J., Xu, H., Lv, B., Yuan, C., Tian, S. and Tian, Y., 2019. An Automatic Trigged Rectangular Rapid Flashing Beacons (RRFB) System Using the Roadside LiDAR Sensor. IEEE Access, 7, pp.163831-163839.
- Wu, J., Xu, H., Yue, R., Tian, Z., Tian, Y. and Tian, Y., 2019. An automatic skateboarder detection method with roadside LiDAR data. Journal of Transportation Safety & Security, pp.1-20.
- Lv, B., Xu, H., Wu, J., Tian, Y. and Yuan, C., 2019. Raster-based Background Filtering for Roadside LiDAR Data. IEEE Access.
- Chen, J., Xu, H., Wu, J., Yue, R., Yuan, C. and Wang, L., 2019. Deer Crossing Road Detection with Roadside LiDAR Sensor. IEEE Access. 2169-3536, Page 1-3, 2019.
- Cui, Y., Xu, H., Wu, J., Sun, Y. and Zhao, J., 2019. Automatic Vehicle Tracking with Roadside LiDAR Data for the Connected-Vehicles System. IEEE Intelligent Systems. page(s): 1-8 Print ISSN: 1541-1672, 2019.
- Zhang, Y., Yao, E., Zhang, R. and Xu, H., 2019. Analysis of elderly people's travel behaviors during the morning peak hours in the context of the free bus program in Beijing, China. Journal of Transport Geography, 76, pp.191-199.
- Wu, J., Xu, H., Zheng, Y., Zhang, Y., Lv, B. and Tian, Z., 2019. Automatic Vehicle Classification using Roadside LiDAR Data. Transportation Research Record, p.0361198119843857. Volume: 2673 issue: 6, page(s): 153-164, 2019.
- Wu, J., Xu, H., Lv, B., Yue, R. and Li, Y., 2019. Automatic Ground Points Identification Method for Roadside LiDAR Data. Transportation Research Record, p.0361198119843869. Volume: 2673 issue: 6, page(s): 140-152, 2019.
- Wu, J., Xu, H. and Liu, W., 2019. Points Registration for Roadside LiDAR Sensors. Transportation Research Record, p.0361198119843855.
- Wu, J. and Xu, H., 2019. Annual Average Daily Traffic Prediction Model for Minor Roads at Intersections. Journal of Transportation Engineering, Part A: Systems, 145(10), p.04019041..
- Wu, J., Tian, Y., Xu, H., Yue, R., Wang, A. and Song, X., 2019. Automatic ground points filtering of roadside LiDAR data using a channel-based filtering algorithm. Optics & Laser Technology, 115, pp.374-383.
- Bin, L., Hao, X., Jianqing, W., Yuan, T., Sheng, T. and Feng, S., Revolution and rotation-based method for roadside lidar data integration. Optics and Laser Technology, 119.
- Yue, R., Yang, G., Tian, Z., Xu, H., Lin, D. and Wang, A., 2019. Microsimulation Analysis of Traffic Operations at Two Diamond Interchange Types. Journal of Advanced Transportation。 2019, Article ID 6863480, 11 pages, 2019.
- Zheng, J., Xu, B., Wang, X., Fan, X., Xu, H. and Sun, G., 2019. A portable roadside vehicle detection system based on multi-sensing fusion. International Journal of Sensor Networks, 29(1), pp.38-47.
- Zhao, J., Xu, H., Liu, H., Wu, J., Zheng, Y. and Wu, D., 2019. Detection and tracking of pedestrians and vehicles using roadside LiDAR sensors. Transportation research part C: emerging technologies, 100, pp.68-87.
- Wu, J., Xu, H., Zheng, Y. and Tian, Z., 2018. A novel method of vehicle-pedestrian near-crash identification with roadside LiDAR data. Accident Analysis & Prevention, 121, pp.238-249.
- Wu, J. and Xu, H., 2018. Driver behavior analysis on rural 2-lane, 2-way highways using SHRP 2 NDS data. Traffic injury prevention, 19(8), pp.838-843.
- Zhao, J., Xu, H., Wu, J., Zheng, Y. and Liu, H., 2018. Trajectory tracking and prediction of pedestrian's crossing intention using roadside LiDAR. IET Intelligent Transport Systems, 13(5), pp.789-795.
- Sun, Y., Xu, H., Wu, J., Zheng, J. and Dietrich, K.M., 2018. 3-D data processing to extract vehicle trajectories from roadside LiDAR data. Transportation research record, 2672(45), pp.14-22.
- Wu, J., Xu, H., Sun, Y., Zheng, J. and Yue, R., 2018. Automatic background filtering method for roadside LiDAR data. Transportation Research Record, 2672(45), pp.106-114..
- Yang, G., Yue, R., Tian, Z. and Xu, H., 2018. Modeling the Impacts of Traffic Flow Arrival Profiles on Ramp Metering Queues. Transportation Research Record, 2672(15), pp.85-92.
- Wu, J., Xu, H. and Zhao, J., 2018. Automatic lane identification using the roadside LiDAR sensors. IEEE Intelligent Transportation Systems Magazine. PP(99):1-1.
- Wu, J. and Xu, H., 2018. The influence of road familiarity on distracted driving activities and driving operation using naturalistic driving study data. Transportation research part F: traffic psychology and behaviour, 52, pp.75-85.
- Yang, G., Tian, Z., Wang, D. and Xu, H., 2018. Queue length estimation for a metered on-ramp using mesoscopic simulation. Transportation Letters, pp.1-10.
- Wu, J. and Xu, H., 2017. Driver behavior analysis for right-turn drivers at signalized intersections using SHRP 2 naturalistic driving study data. Journal of safety research, 63, pp.177-185.
- Yang, G., Tian, Z., Xu, H., Wang, Z. and Wang, D., 2018. Impacts of traffic flow arrival pattern on the necessary queue storage space at metered on-ramps. Transportmetrica A: Transport Science, 14(7), pp.543-561.
- Sun, Y., Xu, H., Wu, J., Hajj, E.Y. and Geng, X., 2017. Data processing framework for development of driving cycles with data from SHRP 2 Naturalistic Driving Study. Transportation Research Record, 2645(1), pp.50-56.
- Wang, Q., Zheng, J., Xu, H., Xu, B. and Chen, R., 2017. Roadside magnetic sensor system for vehicle detection in urban environments. IEEE Transactions on Intelligent Transportation Systems, 19(5), pp.1365-1374.
- Yang, G., Wang, Z., Xu, H. and Tian, Z., 2017. Feasibility of using a constant acceleration rate for freeway entrance ramp acceleration lane length design. Journal of Transportation Engineering, Part A: Systems, 144(3), p.06017001.
Selected research projects
- PI, Multimodal Traffic Mobility and Safety Data Service with LiDAR 2023-2025, RTC Washoe Nevada, $230,000, 2023-2025
- PI, LiDAR Data Collection and Analysis for Safety Management Plans, Nevada Department of Transportation, $150,000, 2023-2024
- PI, Extraction of MIRE FDE from NDOT Mobile LiDAR Data, Nevada Department of Transportation, $94,456, 2023-2024
- PI, Development of a GIS Tool for Rolling-mile Calculation, Nevada Department of Transportation, $55,390, 2023-2024
- PI, University of Nevada Support Services to NDOT Traffic Safety Engineering, Nevada Department of Transportation, $600,000, 2023-2027
- PI, Multimodal Traffic Mobility and Safety Data Service with LiDAR 2022-2023, RTC Washoe Nevada, $100,000, 2022-2023
- PI, Before-after Study with LiDAR for the Reno Micro-mobility Pilot Program, RTC Washoe Nevada, $111,650, 2022
- PI, Analysis of Advanced Signal Warning Systems on Intersection Safety with LiDAR, $40,000, HDR, 2022
- PI, Midtown Virginia St. BRT – Post Construction Traffic Study with LiDAR, RTC Washoe Nevada, $49,775, 2021-2022
- PI, LiDAR Matrix, NSF I-Corps, $50,000, 2021-2022
- PI, UNR Support for NDOT Traffic Safety Data (2021-2022), Nevada Department of Transportation, $75,277, 2021-2022
- PI, Automatic Road Feature Extraction from State-Owned Mobile LiDAR Data for Traffic Safety Analysis and Prediction, U.S. Department of Transportation, $297,538, 2020-2022
- PI, Comparison and Evaluation of Roadside Animal Sensing and Driver Warning Systems, Nevada Department of Transportation, $299,600, 2020-2023
- PI, Street Light Illumination Data Collection and Analysis study, Nevada Department of Transportation, $59,068, 2020
- PI, Pilot Deployment of Roadside LiDAR in City of Henderson NV, Regional Transportation Commission of Southern Nevada, $86,071, 2018 - 2020
- PI, Proof-of-Concept Research of Roadside LiDAR Sensing Multimode Traffic, Nevada Department of Transportation, $313,397, 2018 - 2021
- PI, Pilot Applications of Roadside LiDAR Technologies in Washoe County, Regional Transportation Commission – Washoe County, $250,000, 2018 - 2020
- PI, Data Collection of Wildlife Animals Crossing I80 in Eastern Nevada and USA Parkway, SOLARIS UTC and Nevada Department of Transportation, $136,051, 2018-2019
- PI, Development of a Nevada wildlife-fencing GIS dataset, SOLARIS UTC and Nevada Department of Transportation, $145,817, 2018-2019
- PI, University of Nevada Support Services to NDOT Traffic Safety Engineering, Nevada Department of Transportation, $500,000, 2017-2022
- PI, Developing a Quality of Signal Timing Performance Measure Methodology for Arterial Operations, Nevada Department of Transportation, $272,986, 2017-2020
- PI, Development of Nevada Safety Performance Functions for Rural Two-Lane, Two-Way Highways, Nevada Department of Transportation, $41,745, 2018-2019
- PI, High-Resolution Micro Traffic Data from Roadside LiDAR Sensors for Connected-Vehicles and New Traffic Applications, SOLARIS UTC and Nevada Department of Transportation, $173,670, 2017-2018
- PI, Safety Benefit-Cost Analysis of Roundabouts, Nevada Department of Transportation, $52,932, 2017
- PI, Before-and-after Data Collection of Complete Streets, Nevada Department of Transportation, $40,872, 2017-2018
- PI, Correlation Analysis of Nevada Crash Data and ITS Sensor Data, SOLARIS UTC and Nevada Department of Transportation, $52,447, 2016-2017