By Tom Edwards
BBC London's Transport Correspondent
When you turn up at a Tube station and you read a sign saying, "closed due to engineering works", it is annoying and frustrating and a frantic search for a bus or cab soon begins.
The Tube upgrade programme will deliver nearly 30% more capacity
A massive upgrade of the Tube network is currently under way, which has meant travellers have so far experienced weekend closures on some lines and a 2200 GMT finish on the Victoria Line.
With the work planned to take another eight years, it looks like there will be more disruption to come.
The Northern Line is now getting weekend closures, part of the line from Morden to Tooting has been closed this weekend, as is the Victoria and Circle line.
London Underground (LU) has said it will be worth it as it will mean 30% more capacity across the network.
But while billions of pounds are being spent upgrading the network, many businesses are not happy.
Camden Town Unlimited (CTU), which represents many companies in the north London area which is on the Northern Line, said the proposed closure of the Tube station could cause small traders real problems.
It said closures of the line could decimate the night time economy there.
Chris Shaw, from CTU, said: "I think the impact could be devastating.
Camden Town station could close for 30 weekends in 2011
"There are about 20,000 people in the town centre - how will they get away? You can't rely on replacement buses for that.
"Most businesses around here make all of their profits and most of their income on Friday, Saturday and Sunday.
"If those days and nights are not available to them, then businesses will go to the wall.
"We have a number of businesses hanging on by a thread and this will just push them over the edge."
London Underground and the contractor Tube Lines is currently arguing about how many weekends the Northern Line needs to be closed for.
The traders support an upgrade, but say it should be kept to a minimum.
The point is the Tube needs upgrading - it is old.
And with an increasing population more capacity is needed. If the work is not carried out then the Underground will get more and more crowded.
Davis Waboso, director for line upgrades at London Underground, said: "We have an infrastructure that is 150-years-old and assets that are in desperate need of renewal.
"We have got to upgrade to increase capacity, we don't have an option, and there is an inevitable degree of disruption.
"We are very sympathetic [to the disruption caused] and put our customers first in everything, so we are doing everything we can to minimise the disruption."
More frequent trains
The Tube upgrade programme will deliver nearly 30% more capacity across the network.
It will also deliver faster, more frequent trains and passengers are, after two years, starting to see results.
For example, since the Victoria Line upgrade they can now run more trains closer together.
And new trains are starting to be run on the line. By 2012, 47 new trains will be in service.
None of which makes much difference to stress levels when you are late and you are greeted with a closed station and a replacement bus service.
But this is short-term pain for long term gain, according to LU.
The advice for the next eight years - as ever - is check before you travel.