The state government’s new public transport fare system, MyZone, comes into effect tomorrow. It is intended to simplify fares ahead of a successor to the abandoned T-card initiative, but it introduces its own anomalies.Setting fares involves trade-offs between satisfying users, operators and funding agencies. Simplifying the system for one group may make things more complicated for others.The number of passengers using public transport is affected by the quality of service, and by the cost and simplicity of buying a ticket. MyZone will lower fares for many, and the same ticket can be used on public and private buses. But there will still be inequity between modes of transport.Train fares are based on distance travelled, while bus fares are almost flat; fares over six sections – or 9.6 kilometres – will cost the same. A bus journey of 10 kilometres will cost $4.30, while a train journey of equivalent length will cost $3.20. But bus users can travel as far as they like for $4.30, whereas train fares increase with distance until 65 kilometres.For passengers who need to add a bus or ferry to a train trip, there will be MyMulti tickets. They offer unlimited bus and ferry travel and are almost zonal for trains – they will depend on whether a journey is within a designated zone, rather than increasing with distance. But a strange quirk means prices depend on how far from the city the train journey is.For instance, a traveller taking a bus to Quakers Hill then a train to Westmead will need a MyMulti3, at $57 a week. But someone going by bus to Strathfield, then by train to Parramatta will only need a MyMulti1, at $41 a week. The train journeys are about the same distance, but getting on a train further from the city costs more.For a single bus journey, MyZone proposes the TravelTen for 10 trips. Charging by trip means it costs less for direct journeys so route planning concentrates on journeys not involving any changes, rather than for maximum efficiency.Take the trip from Bondi Beach to the city. The direct bus route is cheaper but takes longer than changing from bus to train at Bondi Junction. If the fare system allowed easy changing without a financial penalty, network planners could focus on reducing overall travelling times. Passengers may not like interchanges but they hate interchanges that cost more. MyZone has not changed this.Additionally, those who use the light rail or private ferries are excluded entirely, as those fares are not part of MyZone.Sydney’s roads and public transport are at or near capacity in peak hours. Many passengers travel during peak hours because there are more frequent services, not because they need to travel then. Most big cities discount off-peak travel. While the new MyTrain tickets will give off-peak discounts for return trips, there is no equivalent for buses or ferries which see the same phenomenon.Pre-pay bus tickets have been a success because without drivers having to sell tickets, buses move more quickly between stops. But from tomorrow, private bus operators will have to manually mark 10-trip tickets, which may slow things down.Realistically, MyZone fares will not improve operational efficiency; we need to wait for electronic ticketing for this.And there are knock-on impacts of MyZone, like creating an incentive to live further from the city. Bus fares do not increase after about 10 kilometres, and train fares are the same for any distance over 65 kilometres.This fare structure will pressure urban planners to expand suburbs on the fringe of Sydney, increasing the risk of urban sprawl running counter to the state government’s Metropolitan Strategy.MyZone fares are simpler than their predecessors, but fare equity, off-peak pricing and the cost of interchange will require more thought.Professor Corinne Mulley holds the chair in public transport at the University of Sydney.