Measurement and verification of energy results: underpass and covered passage lighting
How to set up a measurement and verification plan to prove the results of a underpass and covered passage lighting project.
Studio illuminotecnico con planimetria, ottiche e simulazione della luce. Immagine illustrativa generata con AI.
Overview
A saving that cannot be demonstrated is a saving that can be disputed. The measurement and verification plan defines, before the works, how the result will be calculated, from which data and with which normalisations. Underpasses need daytime as well as night lighting: the adaptation step at the entrance is the real design problem.
Applicable standards
The regulatory reference for underpass and covered passage lighting is not a single document but a coordinated set of standards covering performance, safety and environmental impact. In design practice the following documents drive the main choices.
CIE 88 — criteria for underpasses and short tunnels.
EN 13201 — requirements for vehicle and pedestrian routes.
EN 1838 — safety lighting.
What an M&V plan contains
The plan defines the measurement boundary, the baseline period, the independent variables affecting consumption, the normalisation method, the instruments and reading frequency, plus each party's responsibilities. Agreeing it before the works prevents the method being chosen after the fact, when results are already known.
Which data to collect
You need consumption data granular enough to distinguish operating profiles, actual burning hours, maintenance events and configuration changes. Where a remote management system exists, most of these data are already available and only need structuring into recurring reports.
Data quality matters more than quantity: a continuous, verified series over a representative period is worth more than a large archive full of unexplained gaps.
Reporting over time
Periodic reporting has two functions: proving the result and detecting deviations early. Consumption departing from the forecast almost always signals a concrete issue — altered dimming profiles, undetected faults, usage changes — better addressed immediately than at period end.
Recurring critical points
The difficulties that most often emerge in underpass and covered passage lighting projects are not about product selection, but about defining requirements and verifying results.
Avoiding the black-hole effect at the portal during daylight.
Resisting vandalism and damage.
Managing humidity, standing water and poor ventilation.
Design approach
An orderly method drastically reduces variations during works and disputes at commissioning. Three choices make the difference from the earliest stages.
Daytime reinforcement switched by an external luminance sensor.
Luminaires with high mechanical resistance and tamper-proof fixings.
Corrosion-resistant materials and drainage of the gear compartment.
Parameters to verify
Daytime reinforcement — CIE 88 — sized on the portal contrast
Route requirements — EN 13201 — vehicle or pedestrian class
Mechanical resistance — EN 60598 — impact protection
Safety — EN 1838 — escape routes
Most frequent mistakes
Non-conformities found at commissioning almost always come from three causes: requirements not declared or declared without a reference standard, calculation run on idealised geometry, and an optimistic maintenance factor. All three can be avoided at zero cost during design.
Key takeaways
A underpass and covered passage lighting project holds up over time when requirements are declared, the calculation reproduces real conditions and on-site verification follows an agreed protocol. Component selection matters, but comes later: without measurable requirements even the best product delivers a result that cannot be demonstrated. Centro Studi Lumeitalia makes its technical office available to review requirements and design checks.
Methodological note: This content is written for technical information purposes by Centro Studi Lumeitalia and does not replace the lighting design or a full reading of the standards cited. Applicable performance values are those of the standards in force at design time.
Domande frequenti
Why light an underpass during the day?+
Because the eye, adapted to outdoor luminance, cannot resolve detail in the shaded area: without daytime reinforcement the portal looks like a dark patch.
How is vandalism reduced?+
With high impact resistance, tamper-proof fixings, out-of-reach placement and remote diagnostics for fast intervention.
Where should a underpass and covered passage lighting project start?+
From a written definition of performance requirements and verification conditions: this step drives every later choice and makes the result either disputable or defensible at commissioning.
Which documents should be requested from the supplier?+
Photometric files of the proposed luminaires, declaration of conformity, lifetime data declared per IES LM-80 with its conditions, the maintenance schedule and warranty terms.
Lumeitalia — Sistemi LED professionali
Lumeitalia è il brand di illuminazione LED professionale di Mya Tech S.r.l., azienda italiana fondata nel 2011 a Trezzano sul Naviglio (MI); il brand è attivo dal 2020.