| An increase in the number of elderly passengers on a bus and mix traffic flow will lead to higher levels of mental fatigue for a city bus driver [92] | Taiwan (China), 2019 |
| Driving under negative passenger behavior affects the satisfaction of bus drivers [93] | Korea, 2019 |
| Road condition pressure affects the satisfaction of bus drivers [93] | Korea, 2019 |
| Buses are too crowded cause unwanted arousal of passengers [68] | UK, 2007 |
| In terms of passenger load, 8 - 18 (people) is a threshold below which momentary mood gets worse, and 19 - 29 (people) is the other threshold beyond which momentary mood deteriorates considerably. Further, regarding bus micro-environmental indicators, the optimal exposure level to noise is in the 0 - 65 dB range [94] | China, 2020 |
| A timetabling method that considers passenger satisfaction (reducing crowding) is proposed for optimizing the bus frequency and headway in Beijing [95] | China, 2019 |
| Costs |
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| Bus drivers who received eco-driving training significantly improved fuel economy [96] | UK, 2015 |
| DB can lead up to 27% of fuel saving in a bus route in Rome [97] | Italy, 2013 |
| The high correlation between aggressiveness and energy consumption implies that particular attention must be paid to limiting high-speed accelerations of city buses [98] | Finland, 2018 |
| The bus operating speed has the greatest influence on the fuel consumption costs of intercity buses [99] | Serbia, 2017 |
| Vehicle costs and general costs related to accidents involving vehicle repairs, unavailability of vehicles, towing, travel delay [100] | Australia, 2014 |
| Bus operating costs increases due to the cost of the additional time when congestion occurs [101] | USA, 2003 |
| Fluctuation of traffic volume has an impact on the fuel consumption costs of buses [99] | Serbia, 2017 |
| External costs such as accident risk and pollution are imposed on non-users; Traffic congestion results in incremental vehicle operating costs; Operating costs for drivers comprise oil and tire wear costs [102] | Canada, 2010 |
| Bus movement implies materials costs (e.g., tire lubricants, tire wear) [103] | Italy, 2016 |
| Planning of a suitable bus lane infrastructure will help reduce the bus operating cost [104] | China, 2017 |
| Deteriorating riding quality and poor infrastructure cause higher vehicle operating costs [105] | South Africa, 2015 |
| Terrain type, road surface, and IRI have an impact on the fuel consumption costs of buses [99] | Serbia, 2017 |
| The average bus stop density and percentage of bus lanes have significant influences on cost-inefficiency differentials [106] | China, 2017 |
| Revenues and vehicle efficiency |
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| Psychological symptoms, sensation seeking, and aggression predicted the preferred speed [43] | Türkiye, 2003 |
| The number of passengers has little direct influence on the predictive power of acceleration behavior [107] | Sweden, 2007 |
| Bus passenger boarding/alighting times increase with an increase of the number of alighting passengers, the number of boarding passengers, and the number of passengers on board bus [80] | USA, 2019 |
| Service (frequency and speed, cleanliness, space, temperature, proximity, and fare), comfort (travel experience), and personnel (behavior of the staff—safety and courtesy) affect the number of passengers [108] | Spain, 2013 |
| Bus layout designs (wheel position, number of doors...) affect attractions of passengers [109] | Euro, 2014 |
| Increasing the speed and reducing the abrupt breaking of autonomous buses will enhance users’ experiences and attract passengers [110] | Norway, 2021 |
| Substantial time savings can be obtained if payment methods are upgraded [73] | Australia, 2013 |