The adoption of specifications, the issuing of mandates for standards and the selection and deployment of ITS applications and services shall be based upon an evaluation of needs involving all relevant stakeholders, and shall comply with the following principles. These measures shall:

(a) Be effective

make a tangible contribution towards solving the key challenges affecting road transportation in Europe (e.g. reducing congestion, lowering of emissions, improving energy efficiency, attaining higher levels of safety and security including vulnerable road users);

(b) Be cost-efficient

optimise the ratio of costs in relation to output with regard to meeting objectives;

(c) Be proportionate

provide, where appropriate, for different levels of achievable service quality and deployment, taking into account the local, regional, national and European specificities;

(d) Support continuity of services

ensure seamless services across the Union, in particular on the trans-European network, and where possible at its external borders, when ITS services are deployed. Continuity of services should be ensured at a level adapted to the characteristics of the transport networks linking countries with countries, and where appropriate, regions with regions and cities with rural areas;

(e) Deliver interoperability

ensure that systems and the underlying business processes have the capacity to exchange data and to share information and knowledge to enable effective ITS service delivery;

(f) Support backward compatibility

ensure, where appropriate, the capability for ITS systems to work with existing systems that share a common purpose, without hindering the development of new technologies;

(g) Respect existing national infrastructure and network characteristics

take into account the inherent differences in the transport network characteristics, in particular in the sizes of the traffic volumes and in road weather conditions;

(h) Promote equality of access

do not impede or discriminate against access to ITS applications and services by vulnerable road users;

(i) Support maturity

demonstrate, after appropriate risk assessment, the robustness of innovative ITS systems, through a sufficient level of technical development and operational exploitation;

(j) Deliver quality of timing and positioning

use of satellite-based infrastructures, or any technology providing equivalent levels of precision for the purposes of ITS applications and services that require global, continuous, accurate and guaranteed timing and positioning services;

(k) Facilitate inter-modality

take into account the coordination of various modes of transport, where appropriate, when deploying ITS;

(l) Respect coherence

take into account existing Union rules, policies and activities which are relevant in the field of ITS, in particular in the field of standardisation.