No.	Types of bus interaction	Sustainable bus system viewpoint
		Society			Economy		Environment	Institution
		a	b	c	d	e	f	g	h
		Safety and Security	Accessibility	Quality of service (Q.O.S)	Costs	Revenue and vehicle efficiency	Emission and noise	Planning and management	Public policy
1	Bus- bus driver	Driving behavior (DB) is the biggest contributor to traffic safety and accidents. Neuro- transportation is a potential research direction for the future	DB (relating to floor ramp) affects to accessibility of passenger	Driving style, behavior contribute to passenger satisfaction.	Eco-driving training and good driving behavior regarding acceleration significantly improve fuel economy	Psychological symptoms, sensation seeking, aggression, smoking habit, alcohol usage affect bus speed	DB patterns, speed, brands of buses affect emission and noise. Engine generates noise. Number of stop & go cycles, and acceleration affect emission	Location and number of bus stops, camera surveillance, enforcement activities, manned and automated enforcement determine DB	Training and enforcement programs reduce hard braking and acceleration, aggressive patterns, unsafe lane change
2	Bus- passengers	Most injuries of bus passengers and severity of these injuries are commonly caused by impact with elements inside the bus.	Low and equal-size steps or no steps in bus entrance and well-designed handrails make boarding & alighting easier	The adequacy and quality of the bus components are the two main factors affecting comfort and satisfaction	Costs of maintenance and improvement of components	Cleanliness, air quality, high speed, decoration, temperature, and convenient payment increase ridership & revenue	Passenger load increases fuel consumption, emission, and noise. Boarding and alighting of passengers increase air pollution	Buses provide a real-time information system for passengers	Investments on bus design help attract more passengers. A car restriction policy increases public transport passenger
3	Bus-other vehicles	A wide range of vehicles, heavy vehicles, high speeds, old drivers result in a high possibility of severe collisions	Other vehicles (ex. motorcycle, bicycle) prevent accessibility of passenger to bus at bus stop	Optimal bus frequency results from a balance between passengers’ crowding inside bus and congestion outside	Operating cost increases with traffic congestion. Accidents generate vehicle and general costs	Interaction between bus and other vehicles is the main reason for reducing bus speed	Bus and other movements in rush hour, mixed traffic cause higher total fuel consumption and emission	Bus priority schemes and techniques have proven to be effective for faster travel times	Limiting number and usage of cars are effective regulations for a sustainable public transport
4	Bus-other road users	The severity of bus accidents is positively related to vulnerable road users and illegal DB	Perception of others to bus movement affects to their reaction and accessibility	Bus movement affects to comfort, satisfaction of other road users	External costs such as accident risk and pollution are imposed on non-users	Interaction affects to ability of using bus of others, ridership	Bus movement affects to others perception & DB, emissions & noise	Planning of bus stops, lanes, hubs affect interaction	Restrictive and promotional policies reduce other road users
5	Bus- environment	Infrastructure quality, road status, and road design have a certain influence on the speed and safety of buses	Bus movement, its components, bus lane and bus stop affect accessibility	Poor layout, and infrastructure and road surface quality cause discomfort of passengers	The terrain type, road surface, and infrastructure quality have an impact on the operating cost	A good infrastructure design (number and location of bus stops, crossings, …) helps increase bus speed	Pavement type, thickness, void ratio, particle size, aging, and abrasion of road have influence on noise from tire/pavement interaction	Segregated and priority lanes, well-organized bus stops help enhance speed. In bus lines with more stops, speed is low	A high level of investments in the transportation system is a positive aspect to assure a good bus system