This dataset provides ready-to-use door-to-door public transport travel time estimates for each of the 230,000 2011 Census output areas (OA) in Great Britain (GB) to every other OA reachable within 150 minutes during the morning peak for the year 2023. This information comprises an all-to-all travel time matrix (TTM) at the national level. In addition, the dataset includes two more TTMs at the lower super output area (LSOA) and the data zone (DZ) levels (42,000 LSOA/DZ units in total). These are estimated for two times of departure, specifically during the morning peak and at night. Altogether, these TTMs present a range of opportunities for researchers and practitioners, such as the development of accessibility measures, spatial connectivity or modifiable areal/temporal unit problem analyses, and the evaluation of public transport service changes throughout a day. ##Access to the data## To request access to Public transport travel time matrices for Great Britain output areas level data (TTM 2023), please get in touch by clicking [Request Data](https://data.ubdc.ac.uk/data-service/access-request "title")