I stand corrected. Let my modify my original statement by saying that 'adding' seems to imply that no new cars will be allowed in Singapore. Which, of course, isn't true.
My concern was that without reading the article, few people may know that in Singapore, most cars are usually removed (retired) from road use after 10 years.
In other words, I think 'stop increasing' sums up the situation better than 'stop adding'.
Bloomberg has also updated its headline to read: "Singapore Will Stop Increasing Car Numbers From February 2018"