Common Causes of Boston Car Accidents and How Liability Is Determined

Not every car accident has the same cause, and not every accident involves a single party who is clearly at fault. In Boston, where dense traffic, aging infrastructure, and heavy pedestrian activity are constants, the circumstances that lead to a crash can be layered – and so can the question of who is legally responsible.

Understanding the most common causes of car accidents in Massachusetts, and how fault is actually established, matters more than most people realize. The cause of the crash shapes what evidence is relevant, who can be held liable, and what your claim is ultimately worth. What looks straightforward from the road can become complicated once insurance companies, lawyers, and in some cases courts, start examining the details.

This article covers the most common causes of Boston car accidents, how road conditions and city traffic factor into liability, and what determining fault actually involves when a claim needs to be built.

Distracted Driving

Distracted driving is one of the most prevalent causes of car accidents nationally and in Massachusetts. It covers a broad range of behavior – anything that takes a driver’s attention off the road, whether that is a phone, a dashboard screen, food, a conversation, or something outside the vehicle. But for legal and liability purposes, phone use while driving is the most frequently documented and the most directly tied to Massachusetts law.

Under Massachusetts General Laws Chapter 90, Section 13B, as amended in 2020, no driver may hold a mobile electronic device while operating a vehicle. No one may use a device unless it is in hands-free mode. Reading or viewing text, images, or video on a device is prohibited, with a narrow exception for GPS navigation when the device is properly mounted and does not obstruct the driver’s view. The law applies to all drivers on Massachusetts roads.

Violations carry escalating fines, and a third or subsequent offense triggers an insurance surcharge – along with a mandatory distracted driving education program. First and second offenses do not result in a surcharge. For drivers under 18, or for public transportation operators including bus drivers, a stricter rule applies: no phone use at all, even hands-free (MGL c. 90, § 8M).

In the context of a personal injury claim, a documented violation of this law is meaningful evidence. It does not automatically resolve the fault question, but proof that the other driver was on their phone – through phone records, witness accounts, dashcam footage, or a citation at the scene – is directly relevant to establishing that driver’s negligence. Distracted driving also tends to affect how insurers assess a claim and whether a case is likely to resolve before or after filing suit.

Speeding

Speeding is a contributing factor in a significant share of serious crashes, and Massachusetts is no different from the rest of the country in that respect. The risk is not limited to highway driving – in dense urban environments like Boston, even modest excess speed in areas with heavy pedestrian traffic, narrow lanes, and frequent intersections can dramatically reduce a driver’s ability to respond and stop in time.

From a liability standpoint, speeding is relevant for two reasons. First, a driver who was cited for speeding at the scene has already had a judgment of violation recorded against them, and that matters in how a claim proceeds. Second, even absent a formal citation, evidence of speed – through skid marks, vehicle damage patterns, traffic camera footage, or accident reconstruction – can be used to establish that a driver was traveling faster than conditions safely allowed, regardless of whether they technically exceeded the posted limit.

Massachusetts also recognizes that the appropriate speed for conditions may be lower than the posted maximum. A driver traveling at the speed limit through an intersection in heavy rain with reduced visibility may still be found to have driven negligently if conditions demanded a lower speed. This is a meaningful nuance in cases where a defendant claims they were within the legal limit but surrounding circumstances – weather, visibility, road layout – made that speed unreasonable.

Drunk Driving and OUI in Massachusetts

Drunk driving causes some of the most serious accidents on Massachusetts roads, and when it does, it opens a civil liability picture that extends beyond the standard negligence analysis. In Massachusetts, operating a vehicle under the influence of alcohol or drugs is governed by Massachusetts General Laws Chapter 90, Section 24. A driver is legally impaired per se – meaning without needing further proof of actual impairment – if their blood alcohol content is 0.08% or greater. For drivers under 21, that threshold drops to 0.02%.

The criminal and civil sides of an OUI case are separate proceedings, but they are not unrelated. A criminal OUI conviction is strong evidence of negligence in a civil personal injury case. An OUI charge, even without a conviction, combined with other evidence of impairment, can significantly affect how the civil claim is built and argued. Courts have long recognized that driving while intoxicated represents a serious breach of the duty of care that every driver owes to others on the road.

What many people do not realize is that in a drunk driving accident, the intoxicated driver is not necessarily the only party who can be held liable.

When the Bar or Restaurant Can Be Held Responsible

Massachusetts General Laws Chapter 138, Section 69 prohibits the sale or delivery of alcohol on licensed premises to any intoxicated person. When a bar, restaurant, nightclub, or other licensed establishment serves alcohol to someone who is already visibly intoxicated – and that person then drives and causes an accident – the establishment may share civil liability for the resulting injuries. These are commonly referred to as dram shop cases.

Massachusetts does not have a specific civil dram shop statute. Liability is established through common law negligence, using MGL c. 138, § 69 as evidence of a breach of duty. To succeed, a claimant must show that the establishment served alcohol to a patron who was visibly intoxicated at the time of service, and that the continued service was a cause of the injuries. It is not enough that the driver had a drink at a bar at some point in the evening. The evidence needs to show that intoxication was apparent and alcohol was still served.

These cases carry their own procedural requirements. Under Massachusetts General Laws Chapter 231, Section 60J, a plaintiff pursuing a dram shop claim must, after filing, submit an affidavit within 90 days that sets out sufficient facts to support the liability theory. Missing that deadline without an extension causes the claim to be dismissed. Evidence in these cases – surveillance footage, point-of-sale records, witness accounts – is time-sensitive, and the case is significantly stronger when action is taken promptly.

Road Conditions and City Traffic in Boston

Boston’s road network presents persistent challenges: potholed streets from repeated freeze-thaw cycles, intersections that predate modern traffic planning, construction zones that shift lane configurations with limited warning, and one of the highest concentrations of cyclists and pedestrians in the country. When road conditions contribute to an accident, liability does not automatically land on the municipality – but it is not automatically off the table either.

Under Massachusetts General Laws Chapter 84, Section 15, cities and towns are liable for personal injury and property damage caused by defects in public ways when the municipality had – or reasonably should have had -notice of the defect and sufficient time to make repairs. The same general principle applies to state-maintained roads under MGL c. 81, § 18, though the damage caps and procedures differ. Both statutes impose statutory caps that significantly limit the amount recoverable against a government entity, and for state road claims under MGL c. 81, § 18, there is no recovery at all for property damage – only for personal injury.

Several things are important to understand about road defect claims. First, the notice window is extremely short – a written claim must be submitted within 30 days of the incident under MGL c. 84, § 18. Missing that deadline bars the claim entirely. Second, snow and ice on public ways is explicitly excluded from road defect liability under MGL c. 84, Section 17. A crash caused by black ice or unplowed snow on a city street does not give rise to a road defect claim under this statute.

Third, and critically for car accidents specifically: under MGL c. 84, § 15, Massachusetts courts have established that a municipality is only liable if the road defect was the sole cause of the injury. If the plaintiff’s own conduct contributed to the crash in any way – or if another driver’s negligence was also a factor – that can bar recovery against the municipality entirely under this statute, even if a genuine road defect existed. This is meaningfully different from the comparative negligence standard that applies to regular driver-versus-driver claims. In practice, it makes road defect claims in car accident cases highly fact-specific and difficult to evaluate without legal guidance, because what looks like a shared-fault accident may or may not support a municipal claim depending on how causation is analyzed.

Separately, if the accident involved a government vehicle or a government employee acting within the scope of their employment, that claim follows a different path – the Massachusetts Tort Claims Act (MGL c. 258, § 4), which requires a written presentment to the appropriate government official within two years of the injury. The 30-day and two-year deadlines are separate obligations, applying to different types of government-related claims, and neither extends automatically to the other.

Construction zones deserve particular attention in the Boston area. Where a private contractor has created or contributed to a hazardous road condition – improperly marked lanes, unsafe temporary surfacing, missing signage – the contractor may be independently liable, separate from any municipal claim. Liability in those situations depends on who controlled the worksite and what safety obligations were in place.

Determining Liability – Who Can Be Held Responsible

In a car accident claim, the question of liability is almost always more complex than it appears at first. Most people think of a car accident as involving two drivers, one of whom was at fault. In practice, multiple parties can share legal responsibility, and identifying all of them matters – both for building the strongest possible claim and for ensuring that available insurance coverage is fully used.

The At-Fault Driver

The at-fault driver is the starting point. Liability is established through evidence of negligence – that the driver failed to exercise the care that a reasonable person would have, and that failure caused the accident and the resulting injuries. Traffic citations, police reports, witness accounts, dashcam or surveillance footage, and physical evidence at the scene all contribute to that analysis. Massachusetts’s modified comparative negligence rule means that if the injured driver also shares some responsibility, their recovery is reduced proportionally – but recovery is not barred unless their share of fault reaches 51% or more.

Employers – When the Driver Was on the Job

If the driver who caused the accident was working at the time – making a delivery, driving a company vehicle, running a work errand – their employer may also be liable under the legal doctrine of respondent superior, which holds employers accountable for the negligent acts of employees acting within the scope of their employment. Commercial vehicles, delivery drivers, rideshare drivers on active trips, and truckers are common examples. Employer liability matters because commercial policies typically carry significantly higher coverage limits than personal auto policies.

Vehicle Manufacturers

If a defect in the at-fault driver’s vehicle contributed to the accident – a brake failure, a tire blowout from a manufacturing defect, an airbag malfunction – the manufacturer or distributor of that component may bear product liability. These cases require technical investigation and expert analysis, but they are a legitimate avenue when the evidence supports it.

Municipalities and the State

As described above, when a road defect contributed to the crash, a municipality or the state may bear liability – subject to the strict notice deadlines, damage caps, and procedural requirements that apply to government claims in Massachusetts. One significant limitation bears repeating: under MGL c. 84, § 15, municipal road defect liability applies only when the defect was the sole cause of the injury. Where driver conduct also played a role, road defect claims become considerably more complex and require careful legal analysis.

Alcohol Vendors

In accidents involving drunk drivers, the establishment that over-served the driver may also carry civil liability, as covered in the dram shop section above. This can be a critical source of additional recovery when the driver’s personal insurance is insufficient to cover the full extent of the damages.

Why Liability Is Rarely Straightforward

Identifying who is responsible, in what proportion, and which insurance policies apply requires investigation that goes well beyond what a police report captures. Evidence fades. Surveillance footage gets overwritten. Witness recollections shift. Phone records require timely requests through the right channels. The window for preserving the evidence that liability determinations depend on is shorter than most people expect.

This is part of why the period immediately following an accident matters so much. The legal question of who caused the crash and who is responsible for the consequences is answered by evidence – and that evidence is most available, most reliable, and most usable earliest in the process. What happens in the weeks after an accident shapes what is possible months or years later when the claim is being resolved.

If you were injured in a car accident in Boston and are uncertain about who may be responsible or how your claim fits together, a free consultation with Larson Law gives you a clear picture of where things stand and what your options are.

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