Refer to figure.

Examine each route carefully:

• The ATS route VLC - A34 - ALT - D - AMR can be followed from VALENCIA (VLC) VOR/DME to ALMERIA (AMR) VOR/DME and it is: 191 NM.
• The ATS route VLC - G850 - AMR can be also followed and it is the shortest route: 180 NM.
• The ATS route VLC - B28 - R47- BLN - M192 - AMR can be also followed, but it is the longest one: 261 NM. This route should be the most appropriate one, in case the LE(R)-63 was activated by a NOTAM, which would restrict any aircraft to pass through, since it is the only one that sidesteps the restricted area.
• The ATS route VLC - A34 - ALT - W810 - VSJ - W820 - AMR can be followed and it is: 195 NM.

"Best route" may be interpreted as, the ATS route which is both the most direct route and can be used at all times.

Aside airways G850, W810 and W820, "2" indicates the Conditional Route Category, according to which these airways are plannable and can be used only during times designated in the Conditional Route Availability Message (CRAM), published at 1500 for the 24 hour period starting at 0600 the next day.

Flights on a CDR 2 ATS route can only be planned when the CDRs are made available through NOTAM, which will notify the vertical limits and duration of availability of the CDR. Whenever an operator plans to use the CDR2 or is required by the Civil ATS unit to use this CDR2, an individual flight plan shall be submitted. In this case, the flight plan should contain in Item 15 the CDR2 to be followed. Under this circumstance, any associated RPL shall be cancelled.

Therefore, the ATS route VLC - A34 - ALT - D - AMR, may be not the shortest and most direst route, in comparison with the shortest one (VLC - G850 - AMR), but it is the best route that can be used at all times.