When should I leave to cross the Causeway?
Tell it when you need to have arrived. It answers with the latest departure that still gets you there, which crossing to use, and how long that crossing is forecast to take. Every figure is one the crossing forecast already published for that hour — this page does the clock arithmetic and nothing else.
Set an arrival time and this will name the latest departure that still gets you there, using the crossing forecast published for that hour.
What this can and cannot tell you
It plans against a forecast of a typical hour, built from drive-time samples taken every ten minutes and averaged by day type. That is the right tool for a trip you are planning, and the wrong one for a trip you are about to start: a lorry fire on the bridge is not in any average. For the next twenty minutes, the live checkpoint wait times are the better read.
It will refuse rather than guess. Hours with too little evidence behind them are published as nothing at all, and this page treats them as nothing at all — it will not quietly rank an unmeasured 03:00 above a well-measured 16:00 because the empty one looks faster.
The forecast has not been scored against what actually happened yet, so treat the crossing time as a planning figure with a range rather than a promise. Where the published spread exists, it is shown beside the estimate.
Questions people ask about departure timing
Why does it tell me the latest time to leave rather than the earliest?
Because leaving early is a real cost. An answer that always says "go now" is not a recommendation, it is a refusal to make one. The planner searches every quarter hour between now and your arrival time, prices both crossings at each one, and returns the last departure that still lands inside your arrival time with your contingency intact.
What is the contingency and where does it go?
It is held back from your arrival time, not added to the queue. Setting 20 minutes means the planner looks for a departure that arrives 20 minutes early, so a queue that runs longer than forecast has somewhere to go. It never changes the forecast crossing time itself.
Where do the crossing times come from?
From the weekly crossing forecast published for each route, which is built from Google Directions samples taken every ten minutes and adjusted for how busy that hour usually runs. This page restates those published figures and does the clock arithmetic. It does not model traffic of its own, does not interpolate between hours, and skips any hour the forecast declined to publish rather than treating it as a quiet one.
Why does it sometimes refuse to answer?
There are three different refusals and they mean different things. If there is no published forecast for the hours between now and your arrival, the page says so and shows no wait and no checkpoint, because an absence of evidence is not an empty road. If nothing arrives in time, it says you cannot make it and shows the arrival the earliest departure actually achieves, so you can see how late you would be. If the arrival time has already passed, it says that instead.
Is this the same answer the app gives?
The checkpoint choice is: the site and the app use the same detour allowances and the same switch thresholds, so they will not send you to different bridges for the same two queues. The timing is a different question — the app shows live queue readings and a best next window, while this page plans against a forecast of a typical hour, so check the live wait times before you set off. The status word can still differ: the app shows a label written alongside its estimate rather than derived from it. Where they disagree, the minutes are the figure to plan on.
Once you know when, work out where
Patterns
Best time to cross the Causeway
The hours that are usually quiet, by day of the week.
Live
Checkpoint wait times right now
What the queues are doing in the next twenty minutes.
Outbound
Singapore to JB traffic
Woodlands against Tuas for the crossing into Johor.
Return
JB to Singapore traffic
The return queue, which is a different queue entirely.
Guide
The weekday commuter guide
Departure timing for people who do this every day.
Alternative
Crossing by bus instead
When the queue makes driving the wrong choice.