Services to Dudley, Sedgley, Wolverhampton, West Bromwich, Wednesfield, Smethwick, Tividale and Willenhall were reduced on Sunday, October 3.
A National Express West Midlands spokesman said: “We’re temporarily reducing the frequencies on some of our services so that we can ensure consistency and reliability.
“We are really sorry that some of our customers have been experiencing delays to their bus journeys lately.”
More than 20 routes were reduced in Birmingham and in the Black Country the 1, 2, 40, 51, 59, 74, 79, 80, 87 and 529 services were cut back.
National Express West Midlands blamed their recent problems with punctuality on the pandemic and nationwide shortage of drivers.
The spokesman added: “Various issues have been affecting the punctuality and reliability of our services recently including continuing sickness and self-isolation due to the pandemic, as well as the UK-wide difficulties in recruiting drivers and many large-scale sets of roadworks causing congestion and delaying buses.
“From Sunday, October 3, we temporarily tweaked the timetables of some Birmingham and Black Country services to improve their reliability.”
The bus operator is tackling the ongoing problems of their drivers being abused verbally and physically with new sharper cameras helping police apprehend attackers.
A National Express West Midlands spokesperson said: “National Express West Midlands staff have the right to work without fear of assault or intimidation. We will prosecute anybody who does not respect this right.
“All 1,600 of our vehicles are fitted with up to 12 CCTV cameras, and by working together in the Safer Travel Partnership, anti-social behaviour and crime captured on CCTV from National Express West Midlands buses has resulted in a 75% success rate in identifying offenders.”
The spokesman added: “As the region’s largest bus operator, National Express West Midlands employs 3,500 bus drivers. Every year, we continuously recruit and train up hundreds of new and trainee drivers to backfill natural turnover as people retire or move away.”
For more information about the new bus timetables which came in force on Sunday visit www.nxbus.co.uk/west-midlands.