Transportation Design Tricks: No Straight Lines

In this Transportation Tricks mini-series, we take a look at tactics used by transportation designers that we can use to elevate the desirability of your consumer products. Transportation designers are highly trained and skilled in curating a high caliber design aesthetic that grabs and holds the attention of your customers. So, let's harness their tactics to bolster your product's design.

Even on one of the boxiest vehicles, a Jeep, you'll be hard-pressed to find a straight line. Transportation designers know that in order to form a compelling, energetic, and cohesive aesthetic, they must avoid using straight lines.

Let's take a look at what they use instead:

Arced Lines

Even when the vehicle is intended to look blocky, all of the vehicle's edges and parting lines are curved for two reasons:

  1. Strength // Lines that are perfectly straight play a trick on the eye and appear to droop or slump. Even though they are straight as an arrow, flat lines appear to have a slight sag in the belly. The sagging illusion gives off an air of weakness to a vehicle's forms. To counteract this, transportation designers arc all lines. The curve can be very subtle; just enough to add visual strength.

  2. Cohesion // Straight lines give off a stark, unrefined feel, whereas arced lines contribute to a cohesive and fluid aesthetic. The transportation designer adds tension and energy to a vehicle's lines by curving them. These curves make the vehicle's forms approachable and interesting.

Crowned Surfaces

Just as transportation designers avoid straight lines, they too avoid flat surfaces. Whenever possible, a vehicle's surfaces should curve in two directions. Rather than using flat surfaces to build a vehicle's forms, transportation designers use crowned surfaces, also known as complex surfaces.

Similar to arced lines, crowned surfaces do two things:

  1. Strengthen // Crowned surfaces come together to create dynamic, sturdy forms. To counteract the slumping illusion that a flat surface gives, crowned surfaces bow slightly in a positive direction.

  2. Add Interest // By crowning surfaces, transportation designers are able to shape the highlights and reflections that your customer sees. This adds a level of refinement and control to the overall design.


The "No Straight Lines" tactic is a powerful guide when shaping the forms of your product's design. The "No Straight Lines" method isn't a hard rule, (some lines and surfaces just have to be straight) but it is important to understand its significance in giving you the ability to control the desirability of your product's aesthetic.

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