Between Hull and Withernsea there is the main bus 'corridor' via Hedon and along the A1033, plus two 'diversions'; one via Holderness Road and Southcoates Lane in Hull and one via the village off Burstwick. Monday to Saturday daytimes two services per hour can be sustained along the main 'corridor', leaving a choice - share the two 'diversions' out between the two services each hour, or put both diversions on the same hourly journey and run the other hourly journey as a faster service. Since EYMS/East Yorkshire became the sole operator on the corridor, the former has usually been the preference.
In July 2011, the latter was however tried briefly. Service 74 operated between Hull, Hedon and Keyingham (on the A1033), omitting Holderness Road and Burstwick, hourly Monday to Saturday daytimes, with some afternoon journeys extending to Withernsea. Alongside this was hourly service 75 between Hull, Holderness Road, Hedon, Burstwick, Keyingham and Withernsea. By October 2011, the corridor had reverted back Monday to Saturday daytimes to an hourly 76 via Holderness Road but not Burstwick and an hourly 77 via Burstwick but not Holderness Road.
Fast forward over 9 years and on Monday 4th January 2021, East Yorkshire have decided to try again with the one faster and one slower service each hour Monday to Saturday daytimes. Service 75 now operates during this period, as well as continuing in the peaks, evenings and on Sundays, as the slower service via Holderness Road and Burstwick, whilst the faster service omitting both these areas is numbered X7. Services 76 and 77 are withdrawn, which also has the effect of simplifying from three (75/76/77) to two (75/X7) service numbers. Unlike in 2011, all journeys operate between Hull and Withernsea apart from an early morning Hull to Hedon 'short'. For Withernsea this means that rather than a 78 minute journey time on the 77 and an 81 minute journey time on service 76 to Hull, there is now a 73 minute journey time on the X7 and an 86 minute journey time on the 75.