There exist oriented planar graphs with oriented chromatic number at least sixteen

@article{Sopena2002ThereEO,
  title={There exist oriented planar graphs with oriented chromatic number at least sixteen},
  author={{\'E}ric Sopena},
  journal={Inf. Process. Lett.},
  year={2002},
  volume={81},
  pages={309-312}
}
We prove that there exist oriented planar graphs with oriented chromatic number at least 16. Using a result of Raspaud and Sopena [Inform. Process. Lett. 51 (1994) 171–174], this gives that the oriented chromatic number of the family of oriented planar graphs lies between 16 and 80.  2002 Elsevier Science B.V. All rights reserved.