Keith Rollinson, 58, died in hospital following an alleged assault at Elgin bus station in Moray last month.

A 15-year-old boy, who cannot be named due to legal reasons, later appeared in court charged with his murder. The teenager made no plea and was remanded in custody ahead of his next court appearance.

In response to the alleged incident, Unite is urging the Scottish government to implement a series of measures to discourage and combat antisocial and violent behaviour on buses.

The union - which represents thousands of bus workers - has written to First Minister Humza Yousaf asking for support for its "road map" to help improve bus worker safety.

Recommendations include installing panic buttons and protective screens on vehicles, ensuring CCTV is working on buses and at stations, enlisting security officers for all stations and supplying them with stab vests and body-worn cameras, and removing services from problem areas.

Transport Scotland said tackling allegations of antisocial behaviour "are matters for the police and local authorities using the enforcement activities available to them".

Sharon Graham, Unite general secretary, said: "Thousands of bus drivers across Scotland are increasingly anxious and nervous about going to work.

"Unite has set out a road map which would significantly enhance safety and it is one that could be implemented immediately.

"We will do everything possible to ensure that proper measures are in place to protect bus workers."

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Unite has repeatedly called for stronger legal protection for transport workers.

Currently, the Emergency Workers (Scotland) Act 2005 only makes it a specific offence to assault, obstruct or hinder someone providing an emergency service.

Derek Thomson, Unite Scottish secretary, added: "Unite's road map towards greater safety for bus workers is one which can be adopted right away.

"We need support from industry and government to work with us in delivering this plan in the interests of thousands of bus workers and passengers.

"The road map however will only take us so far down the road in addressing the wave of antisocial behaviour and violence towards bus workers. We also need legislation which provides stronger statutory protection for transport workers, which is enforced."

Unite's bus safety 'road map':
• De-escalation training to be given to all staff.
• All buses must be fitted with bandit screens and they must be robust. A replacement plan to be put in place when screens become badly scratched and visibility through the screen is affected.
• Working CCTV on buses and an audit in all locations. A weekly check to be carried out thereafter.
• CCTV in all bus stations to be in good working order and must cover all areas.
• Audible panic buttons in all vehicles. Media and on-bus information to inform the public that an alarm going off on the bus means there is an emergency on or around the vehicle.
• Cab doors fitted with internal locking system and must be robust.
• Bus station to have keypad locks fitted after the council close the facilities, for drivers' safety.
• Police radio in all traffic offices.
• Security in all bus stations. Security to be supplied with stab vest and body-worn cameras.
• Higher police presence at areas of concern.
• Joint communications on how to deal with antisocial behaviour. This must be on the bus and given to staff.
• Joint meetings with the local authority and police, the company and the trade unions.
• In-school safety talks by the company or trade unions.
• A mechanism for the company to identify the small minority who are causing the issues on buses.
• Removal of services in volatile areas of antisocial behaviour.

Transport Scotland said abuse of frontline public transport staff was "completely unacceptable and will not be tolerated".

A spokesperson added: "Tackling allegations of antisocial behaviour are matters for the police and local authorities using the enforcement activities available to them.

"We are continuing to work with these partners to strengthen options to tackle antisocial behaviour.

"Free bus travel is just one of the services provided through the national entitlement card and therefore it would not be appropriate for transport operators to remove cards from cardholders due to the impact this could have on access to other services.

"The legislation underpinning The National Concessionary Travel Scheme for Young People does not make provision for the blocking of cards on this basis."