The challenges faced by the development of smart buses are mainly considered from three perspectives: the perspective of urban residents, the perspective of bus operating enterprises, and the perspective of urban managers.
From the perspective of urban residents, the current problem with bus travel is the long travel time. The reasons for this problem include long waiting times for buses and buses being frequently off schedule. Generally, in order to improve the efficiency of bus operations, buses are often reduced in number and have longer intervals between departures, leading to increased waiting times for residents. In addition, to increase passenger flow, buses may take detours, increasing the non-linear coefficient of the route, resulting in longer travel distances for residents and causing congestion on the roads. Furthermore, there is also a problem with the lack of comfort in bus travel, such as overcrowded buses in hotspots and on certain routes.
From the perspective of bus operating enterprises, there are several issues with current bus travel: Firstly, conflicts between passengers and drivers, bus fires and explosions, bus accidents, bus malfunctions and other accidents are caused by various reasons. Secondly, bus driver recruitment is difficult and costly. Driving buses requires drivers with A3-level licenses. And the high labor costs of drivers, coupled with long working hours, often lead to driver fatigue and pose significant safety hazards. Thirdly, bus travel faces competition from other modes of transportation such as rail transit, electric bicycles, bicycles, and particularly the impact of ride-hailing services. Compared to bus travel, ride-hailing services offer higher service quality, more flexible routes, and greater accessibility.
From the perspective of urban managers, there are the following problems with current bus travel: Firstly, urban-level public transportation decisions need to be more scientific, including the scientific design of bus routes, rapid bus routes, and the implementation of city-level intelligent transportation coordination. Secondly, the timely and accurate release of public transportation travel information is inadequate, with most city bus systems unable to effectively pass travel information. Thirdly, the evaluation of bus service levels is not objective. In many cases, improving bus service levels relies on increasing investment in bus infrastructure, while neglecting other effective means such as intelligent transformation.
The three major development trends of intelligent connected buses
By building intelligent connected buses, it can help achieve smart bus. From the perspective of urban residents, it is necessary to develop “precise buses”. From the perspective of bus operating enterprises, the development of “safe buses” is important. And from the perspective of urban managers, the development of “scientific buses” is beneficial to the city.
1.Precise bus
“Precise buses” have different levels of requirements. First, it is necessary to be on time, that is, residents expect buses to depart and arrive at fixed points on time, so residents can plan their departure time accordingly. Secondly, “customized buses” can be provided, where residents can submit their travel needs through dedicated channels, and bus companies can design bus routes based on residents’ needs and passenger flow situations.
Finally, “smart response buses” can be provided, where residents can choose to pre-book via mobile phones and dynamically generate smart responsive buses, providing more convenient and comfortable personalized travel services.
For different levels of “precise bus” services, intelligent connected technology can provide rich application scenarios. For example, bus priority, green light optimal speed advisory, intelligent platforms (BRT platforms), mobile application information services, L4-level micro-circulation automatic shuttle buses, etc.
Bus priority can achieve resource priority through space and time, where buses have priority access to road space and priority access to road time. Based on intelligent connected C-V2X vehicle-road coordination technology, low-cost and high-precision active real-time adaptive bus priority can be achieved.
Relying on C-V2X long-distance and low-latency capabilities, bus arrival times can be predicted to determine priority timing strategies. Relying on C-V2X high-precision (centimeter-level) positioning capabilities, precise perception of bus position, speed, and acceleration can be achieved, ensuring accurate timing. Dynamically calculating compresses time in various directions based on road congestion conditions, ensuring buses pass directly through by maintaining phases, extending green lights, cutting red lights, inserting phases, and jumping phase sequences. Considering multi-directional priority conflict requests, and prioritizing multiple buses are based on the positions, speeds, directions, passenger loads, punctuality rates, and driver driving intentions at intersections.
Green light optimal speed advisory provides drivers with a suitable speed advice range as buses approach signal-controlled intersections based on road data and real-time signal status data sent by C-V2X roadside units (RSUs), allowing vehicles to pass through intersections economically and comfortably (without needing to stop).
The intelligent platform and the bus intelligent network system achieve data interconnection. And electronic signs can display real-time information about buses, accurately showing bus arrival and departure positions, arrival and departure times, passenger loads, driving speeds, and other information.
Micro-circulation automatic shuttle buses implement fixed-route shuttles with speeds ranging from 20km/h to 50km/h, with L4-level autonomous driving. The application of C-V2X vehicle-road coordination technology will make automatic shuttle buses more precise and safe.
2.Safe bus
“Safe buses” involve various requirements. For buses themselves: vehicle safety is the basic premise of ensuring safe bus operation, including various conditions of the vehicle itself, as well as comprehensive monitoring of the front, rear, driver’s seat, doors, and compartments. For drivers and passengers: driver’s non-standard operations and behaviors, as well as long-term fatigue driving, are important reasons for bus accidents. In addition, dangerous behaviors of passengers, such as grabbing the bus steering wheel, can also seriously endanger bus safety. For traffic environments and other traffic participants: extreme and adverse traffic environments, as well as traffic accidents caused by other traffic participants, can also endanger bus safety.
For the “safe bus” services targeted at different objects, intelligent connected technology can provide rich application scenarios, for example, real-time uploading of bus vehicle status data, intelligent monitoring of driver driving, detection of vulnerable pedestrians and non-motorized vehicles, collision prevention at intersections, monitoring of bridge and tunnel flooding, transformation of L3-level autonomous driving buses, etc.
Real-time uploading of bus vehicle status data integrates onboard terminals (OBUs) with CAN buses, supporting vehicle diagnosis, remote vehicle control, vehicle data reporting, etc.
Intelligent monitoring of driver driving can promptly alert various abnormal behaviors and dangerous behaviors such as fatigue driving, distracted driving, smoking, and making or answering phone calls.
Detection of vulnerable pedestrians and non-motorized vehicles and collision prevention at intersections can collect traffic information at intersections through roadside intelligent devices, generating traffic situation reports. When pedestrians and non-motorized vehicles enter motor vehicle lanes, timely alerts are issued to buses. Roadside edge computing devices can also make collaborative decisions, broadcasting driving suggestions to buses, reducing the probability of traffic accidents.
Bridge and tunnel flooding monitoring detects the condition of bridges and tunnels through roadside intelligent devices, and sends advance warnings to buses entering the roadside via C-V2X RSUs.
Transformation of L3-level autonomous driving buses allows the system to complete most driving operations, only warning the driver when emergency situations occur and the vehicle cannot handle them, and prompting the driver to take over the vehicle. L3-level autonomous driving buses can effectively reduce driver fatigue, freeing drivers from repetitive labor and allowing them to focus more on passenger service. They can also preset trajectories for special road sections, such as bridges and tunnels, in dangerous scenarios. The system presets the highest priority route, preventing drivers and passengers from engaging in harmful behaviors to society. They can also achieve precise parking of buses, with a deviation of no more than 15cm between the first step and the station platform, and a deviation of no more than 20cm in alignment.
3.Scientific bus
“Scientific buses” involve requirements in different dimensions. In the planning and decision-making dimension, scientific design of bus networks, rapid bus routes, etc. are needed. Organic coordination with urban rail transit, last-mile travel, etc. are needed. Integration with smart transportation systems is needed to conduct active traffic control. In the information release dimension, highly integrated data is needed to provide bus information services and traffic accident risk warnings to residents through various touch points.
For different dimensions of “scientific bus” services, intelligent connected technology can provide rich application scenarios, for example, Internet big data applications, optimization of bus networks, integrated travel services, etc. Internet big data applications can explore the travel needs and characteristics of urban residents, providing scientific and reliable data analysis and decision support for the transportation industry, for example, macro-level: inter-provincial/inter-city passenger flow migration, urban passenger flow OD, popular travel areas, etc.; micro-level: real-time passenger flow detection, commuting patterns, crowd portraits, etc.
Optimization of bus networks analyzes the supply of buses in popular areas and identifies areas with low coverage but high travel demand. Integrated travel services provide integrated travel planning based on travel needs, smooth connection of various transportation modes, comprehensive travel information access, and intelligent recommendation of routes based on personal travel preferences.
4.Achievements
With the support of intelligent connected bus technology, the operation time of “precise buses” can be reduced by 15% to 25%, and the speed can be increased by 10% to 20%. The punctuality rate can be increased by 40% to 50%, and the average number of trips can be increased by 25% to 30%. “Safe buses” provide safety management for buses, drivers, passengers, and traffic operations, reducing accident rates by 70% to 80%. “Scientific buses” can effectively improve bus operation supply, with an operational completion rate of up to 98%.