 |  |
You wait all this time for urban road design guidelines and two come along at the same time. The Global Street Design Guide was just released online for free (see previous post), and now the 18 year old TAC Geometric Design Guide for Canadian Roads is being updated (unfortunately its not free). The TAC Guide while being a "guide" is often treated as the "bible" of road design in Canada, with practitioners fearful of straying from it for fear of designing something not to standard. Many of the details in the current 1999 version are considered out of date or just missing, particularly for urban roads and active transportation. Other guides such as the NACTO guidelines are frequently considered more relevant and practical but they're not TAC. Therefore, its great to see the big changes to the TAC Guide focusing on urban road design. There has been a huge shift in the design of urban roads in the past 10 years, never mind the past 18, thus these changes will be welcomed by many who are trying to address urban transportation challenges. Watch the video providing a high level overview of the changes here. But to sum up, it's acceptable to use narrower lane widths than may have been previously preferred, and on roads with a speed of 50 km/h the recommended bicycle facilities are protected lanes or separate paths. Other finer details such as the inappropriateness of clear zones in urban areas and targets speeds rather than design speeds are discussed, and a process for design exceptions is also included and should allow greater freedom with appropriate supporting evidence.