ArcGIS 10.3 or higher with a Desktop Basic (ArcView) license, or ArcGIS Pro 1.2 or higher.You can choose the output location for the new files, and you can compare them with the old ones before manually replacing the old ones with the updated ones.

The tools will not overwrite any existing GTFS files. Then, you can use Step 2 of the tool to update your shapes.txt file and the relevant shape_dist_traveled field entries in stop_times.txt. The chosen shapes will be drawn in the map, where you can edit them.

To edit one or more existing shapes, you give the tool a valid, existing GTFS dataset with a shapes.txt file and choose the shape(s) you want to edit. Then, you can use Step 2 of the tool to update your GTFS files to include this shape information. You can edit this feature class using your own knowledge in order to ensure that the correct paths are truly represented. Step 1 of the tool creates a feature class with good estimates for the on-street paths used in your transit system. To create an entirely new shapes.txt file from scratch, you give the tool a valid, existing GTFS dataset, and the tool creates a new shape.txt file and updates the shape_id field in trips.txt and the shape_dist_traveled field in stop_times.txt. The toolbox is targeted primarily toward transit agencies seeking to improve their GTFS datasets. The Generate GTFS Shapes toolbox produces a new shapes.txt file for your GTFS dataset or allows you to edit an existing one. Read more about the shapes.txt file in the GTFS reference doc. A good shapes.txt file is important in order for GTFS-based routing apps to display transit routes correctly on the map. The optional GTFS shapes.txt file contains the actual on-street paths taken by transit vehicles in your system. See the License for the specific language governing permissions and limitations under the License. Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an 'AS IS' BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Licensed under the Apache License, Version 2.0 (the 'License') you may not use this file except in compliance with the License.

Arcmap field calculation tool