The Welsh Liberal Democrats have promised under-25s free bus travel within the next four years as part of the party's Senedd election manifesto.
The proposals, published on Friday, include a new £500m fund for high streets and town centres and a business rate freeze.
Leader Jane Dodds said every manifesto policy was focused on Wales' recovery - in the economy, the environment and in improving people's mental health.
The election takes place on 6 May.
"Wales is at a turning point and now is the time to decide how we move on from Covid and how we want Wales to look in five years' time," Ms Dodds said.
The Welsh Lib Dems are defending one seat in the 60-member Welsh Parliament.
Kirsty Williams has been part of the current Labour-led Welsh government since 2016, serving as education minister, but is standing down at the election.
WALES ALERTS: Get extra updates on BBC election coverage
The Welsh Lib Dems said free bus travel for the under-25s by 2025 was "part of our plan to give the next generation the best opportunities".
Currently, 16-21 year olds can get a third off bus fares in Wales, while railcards are available across the UK for people aged 16-30.
The manifesto said it would also guarantee the concessionary bus pass for people aged 60 and over.
It promises a new bus law, which the party said would ensure "bus routes meet community needs, ticket fares are affordable and flexible, timetables meet different needs and bus stops and train stations are accessible".
The party said it would invest £1bn a year to "face-up to the climate emergency" with cash aimed at making homes warmer and more energy-efficient, cutting energy bills and investing in "cleaner, greener transport".
It promised to boost mental health spending year on year until it reaches 13% of all NHS spend by 2028.
A £500m Welsh towns fund would invest in town centres and high streets over five years.
The party pledged to freeze business rates for the life of the next Senedd before scrapping them "in the long term".
It also committed to ending homelessness, "by adopting a wide range of policies including increasing the housing support grant".
WALES ELECTION: THE BASICS
What's happening? On 6 May, people will vote to elect 60 Members of the Senedd (MSs). The party that can command the support of a majority of MSs will form the Welsh government. Find out more here.
What powers does the Senedd have? MSs pass laws on aspects of life in Wales such as health, education and transport - and have some tax powers.
Who can vote? Anyone who lives in Wales, is registered to vote and aged 16 or over on 6 May is eligible. You can register to vote online.
Other pledges include:
- Give care workers the Real Living Wage
- Investment to retrofit existing homes to make them more energy efficient
- A Clean Air Act and a commitment to spend 10% of the transport budget on active travel
- Pass a Welsh Language Education for All Act to normalise the Welsh language in education
The party is also opposed to vaccine passports. Ms Dodds told BBC Radio Wales Breakfast they could be discriminatory.
"I think people would be really concerned to know what happens with the data," she said, "some of which, particularly if you've got an underlying medical condition, is particularly sensitive."
The party has also supported an increase to the number of Senedd members to between 80 and 90.
Ms Dodds said the Senedd was "very stretched".
"Here in Wales, we need to make sure that our democratic processes are supported and financed properly," she said.
Analysis by Catrin Haf Jones, BBC Wales political correspondent
"Putting the recovery first" is how the Lib Dems are pitching this election, with that recovery encompassing the economy, the environment and people's wellbeing.
Its biggest pledge is £1bn a year to tackle climate change, something their campaigners say is a big topic on the doorstep - it's also a policy aimed at attracting young votes.
The party's also focusing on local recovery - on towns and high streets - local issues on which the Liberal Democrats tend to do better.
But all this depends on electoral recovery for the party itself.
The party has had a repeated battering at the ballot box over the past six years - in Westminster, where they now have no Welsh MPs, and in Cardiff Bay, where the party's only remaining Liberal Democrat is standing down at this election, having spent the last five years as education minister in the Welsh Labour-led government.
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