What it means
A bridge is an awkward asset to insure. Nearly all of its value sits in one structure that cannot be moved, is exposed to flood, storm, earthquake, ship strike and vehicle impact, and usually has no convenient alternative route if it closes.
The property damage section covers repair or rebuilding of the deck, piers, cables, bearings and approach works, generally on a reinstatement basis so the payout reflects the cost of rebuilding to current standards. Insurers set a sum insured per structure and often add a separate limit for debris removal and emergency works.
The income section is frequently worth more than the structure cover. If a toll bridge closes, the operator loses revenue immediately while still paying staff, interest and maintenance, so business interruption cover replaces that lost income for an agreed period after a waiting period has passed.
Liability cover sits alongside both. A collapse, a falling object or a surface defect can injure users and damage vehicles or vessels, so owners carry public liability limits that are large relative to the structure's value because injury claims can dwarf repair costs.
Pricing depends on engineering, not just on value. Underwriters review the design, age, inspection records, load limits, seismic and flood exposure, and the owner's maintenance regime, and they usually apply a high deductible because small repairs are treated as routine maintenance rather than insured events.
The second meaning of the phrase is unrelated to structures. A broker may arrange a short bridging policy to carry a client from the expiry of one annual policy to the start of another, for example while an asset sale completes, and that cover is temporary by design.
In practice
Real-world examples.
Example
A regional transport authority insures nine road bridges on one schedule with a combined sum insured of $240,000,000. After a flood scours the foundations of one crossing, the policy funds $6,500,000 of underpinning work the authority had no capital budget for that year.
Example
A private concession company running a river crossing is required by its lenders to hold both property and business interruption cover with a minimum 18-month indemnity period. Without that cover the lenders would not have signed off the debt, because toll income is the only source of repayment.
Example
A rail operator buys cover on a steel viaduct and accepts a $1,000,000 deductible in exchange for a lower premium. It reasons that any repair small enough to fall below that figure is work its own maintenance team would do anyway.
Formula
Calculation
Business interruption payout = (Daily income x Days closed) - (Daily income x Waiting period in days)
A toll bridge is insured for $80,000,000 of reinstatement value at a rate of 0.15%, so the property premium is $80,000,000 x 0.0015 = $120,000 for the year. The bridge earns $40,000 a day in tolls, and a barge strike closes it for 90 days. Gross lost income is $40,000 x 90 = $3,600,000, but the policy carries a 14-day waiting period worth $40,000 x 14 = $560,000, so the insurer pays $3,600,000 - $560,000 = $3,040,000 under the income section.Case study
Seen in the real world.
Calder Reach Crossing is an illustrative, fictional toll bridge operated by a small concession company. Its insurance was arranged years earlier on structure value alone, with no income cover, because the directors assumed a modern concrete bridge would simply not stop earning.
In the illustrative scenario a construction barge drifts into a pier during a storm. The repair bill is $4,200,000, comfortably within the sum insured, but the crossing is shut for four months while the pier is assessed and rebuilt, costing about $4,800,000 of toll income that no policy covers.
The company survives by deferring maintenance and renegotiating its loan covenants, then rewrites its insurance at the next renewal to include a 12-month indemnity period for lost tolls. The fictional moral is that for a revenue-earning structure the income cover often matters more than the bricks and steel.
Watch out
Common mistakes.
- Insuring the structure for its historic build cost rather than the current cost of reinstatement, which leaves the owner underinsured after years of construction inflation.
- Buying property damage cover without business interruption cover on a bridge whose tolls service debt, which is where the real financial exposure sits.
- Letting inspection reports lapse, because insurers commonly make regular engineering inspection a condition of cover rather than a suggestion.
Questions
People also ask.
Why are deductibles on bridge policies so large?
Because routine wear and small repairs are expected maintenance, and insurers price for catastrophe events rather than for the owner's upkeep budget.
What is an indemnity period?
It is the maximum length of time the income section will keep paying after a loss, often 12 to 24 months on a major structure, and it should be long enough to cover realistic rebuild times.
Does the policy pay for upgrading the bridge to modern standards?
Only if it includes a public authorities or increased cost of construction extension, otherwise the insurer pays to restore what was there before.
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