Count the normal journeys
List work, study, shopping and regular caring trips for the next month. Include journeys made by different modes rather than assuming one commute describes everything. Public holidays, remote-work days or a temporary schedule change may reduce some trips and add others.
For public transport, compare relevant ticket options using actual expected travel. For driving, fuel is only one cost; parking, tolls and planned maintenance also affect the household budget, even if some belong in separate reserves.
Use a complete monthly estimate
Suppose twenty return journeys cost $6 each and two additional trips cost $8 each. The ticket total is $136. A pass costing $125 would save $11 only if it covers all those journeys and the planned trips occur. If four return journeys disappear, individual tickets would cost $112 instead.
These figures are illustrative. Check current fares, zones, restrictions and expiry before choosing. The cheapest option on a per-trip basis is not useful if it cannot be used on the routes you need.
Leave room for a disrupted journey
Decide whether the allowance includes an occasional alternative when normal travel fails. This could be a modest buffer rather than a separate elaborate category. Keep it proportionate to your actual options and ability to absorb a one-off cost.
At month end, compare planned journeys with actual ones. A repeated change in work location or routine should update the baseline. If a rare taxi or repair causes an unusually high total, annotate it instead of assuming every future month will be identical. Good transport budgeting connects costs to routes, frequency and real alternatives.
