This is a nice paper, describing in detail the RoadSurf model, making it a valuable complement to the newly released, freely available source code for the model. 

The manuscript documents the open-source RoadSurf model which is a beneficial community resource. The paper's greatest contribution is the inclusion of the open source repositories.

The reviewer questions if there are any plans to transition the model from Fortran to Python in the future? If so, this might be worthwhile to mention future development and release plans.

The authors are encouraged to do a relatively minor grammatical check throughout the entire manuscript.

General comments

The  manuscript entitled “RoadSurf 1.1: open-source road weather model library” is a good and important contribution to scientific modelling community as well as to potential end-users from road authorities/directorates and public in many countries. Providing open public access to repository (a good way to go) is crucial and important step for enlarging community of users and developers of the RoadSurf road weather model (RWM). The chosen approach and applied methods are valid as well as results presented and discussed in appropriate and balanced way in the manuscript. The given description (incl. repository) of the RoadSurf 1.1 RWM library is sufficient to reproducibility and traceability of results.

With respect to presentation quality, it would be useful to add an extra paragraph at end of Section 1 to explain content/structure of the manuscript. The section “Conclusions” needs to be re-written and, at least, included sumup paragraphs about RoadSurf Library description on included components and its content; results of evaluation containing not only “words”, but also obtained “numbers” for selected studied period; applicability; plans (if any) for further development/improvement of RoadSurf Library. The illustrations should have a self-explanatory written text in captions to Figures and Tables (see attached file with detailed comments/remarks/suggestions/etc). All Tables in Annex should include additional column containing units for listed variables (Tables 1-3, 5-6) and physical constants (Table 4), or may be? include at the beginning of the manuscript as “Nomenclature”. Frequently, the word “temperature” is used through the text of the manuscript, but it has different “attribution” as: air temperature, road surface temperature, soil temperature, dew point temperature, etc. – these should re- checked and accurately written to avoid a confusion or misleading. It seems that accurate spell-checking of the manuscript text is needed (before submission) to exclude accident mistyping.

Specific comments and Technical corrections are included in the attached file.