BUS passengers on the main route for Bognor Regis face major changes from next week.
More buses are being introduced to the Coastliner 700 service to cope with an increasing number of passengers.
The service westwards to Chichester and Portsmouth will be greatly improved and extended into the night.
But anyone who wants to travel beyond Littlehampton in the other direction will have to change buses.
Andrew Dyer, the managing director of bus operator Stagecoach South, said the changes were among the most comprehensive since Coastliner started in the mid-1970s on a route which had existed for 50 years previously.
“These are the greatest improvements in frequency for many years. Coastliner 700 is one of the busiest routes we have and carried 4.9 million passengers in 2012. Passenger numbers are generally increasing, though it does vary from route to route, and the Coastliner 700 is one of our success stories.”
The changes take effect in the new timetable from Sunday but they will really come into force on Tuesday after the bank holiday.
Passengers will have the choice of six buses an hour to Chichester, instead of the current four, to provide a service every ten minutes.
Three of those buses will travel on to Portsmouth compared to the current half-hourly service.
“We have eight new mid-life buses to enable us to introduce the extra services,” said Mr Dyer. “Twelve brand-new buses will be delivered in the late summer for an investment of nearly £2m.”
They are all double-deckers to meet the rising demand for seats on the 42 buses on the route.
At night, the connection will last until midnight with two b uses an hour from 8.34pm between Flansham and Chichester and an hourly link from Littlehampton to Chichester.
“These are the latest buses we’ve run for many years,” Mr Dyer said. “They are an experiment. We get more evening travellers in the summer and we will see how well-used they are.
“If they are popular, we will continue them in the winter.”
There will be three buses an hour, instead of two, to Littlehampton where passengers will have to change for Brighton.
“Buses will not run beyond Littlehampton going eastwards,” Mr Dyer said. “People who want to do that will have to change.
“It is not ideal but, with a service every ten minutes, they should not have long to wait.
“We have introduced the split to improve punctuality. It is becoming increasingly difficult to keep to the timetable as the roads become more and more congested.
“We think changing buses is the key to keeping them running on time.”
Services between Littlehampton and Arundel will also become more frequent at every 20 minutes compared to half-hourly.
The extra passengers are both fare-paying and using the concessionary fare scheme.