Public transport operator Go-Ahead said its first-year results were in line with expectations but the second half might see a slowdown in revenue growth due to lower passenger journeys in its Go North East and Oxford Bus company.Passenger numbers in Oxford were particularly affected by roadworks, with long delays due to congestion deterring bus travel.As a result, its regional bus business was down 0.5%. However, excluding these businesses, passenger growth was 1.7%.Bus revenue in London also declined year-on-year due to contract losses.The group's revenues rose 13.8% to £1.56bn during the first-half, especially helped by a 18% increase in rail turnover.Profit before tax was also up 10.9% to £44.7m, but adjusted earnings per share declined 9.2% to 75.6p.Go-Ahead said it started "significant" new rail contracts over the period, including GTR, which the group believes it will "shortly become the UK's largest franchise".Chief executive David Brown said: "The board's expectations for the full year results remain unchanged, with second half profits expected to be similar to those in the first half of the year for both our bus and rail divisions."The group remains in a good financial position, with strong cash generation and a robust balance sheet supporting our progressive dividend policy and allowing flexibility to pursue value-adding opportunities."Shore Capital analysts said: "We expect baby steps into new markets to be measured and to require a relatively small investment, which will leave room for a special return of cash."The broker gave a 'hold' recommendation and a 2446p target price.Shares were down 1.27% to 2414p on Thursday at 09:12.